Introduction

The tourism sector is a critical economic industry that plays a pivotal part in the global economy. According to the World Tourism Economic Trends Report (2023), the number of tourists who visited international destinations reached 9.57 billion in 2022, and the total revenue generated by tourism worldwide reached $4.6 trillion. Since 2021, the percentage of worldwide tourism revenue that contributes to the global Gross Domestic Product (GDP) has increased to 4.8%, representing a 0.7% increase from the previous year. The tourism industry has made substantial contributions to economic growth and development1. As economic and social standards rise and people increasingly demand a better quality of life, cultural tourism has not only emerged as a trend in industry development but also as a fundamental aspect of people’s lives2. Consequently, culture is quickly becoming the fundamental basis that supports all tourism-related activities and a crucial factor in the economic success of the tourism industry3. As people’s interest in cultural tourism continues to rise, there is a growing focus on the problem of collaboration between the cultural industry and the tourism industry.

Culture, as a multifaceted entity encompassing customs, arts, and knowledge systems, enriches the tourism sector by adding depth and uniqueness to its offerings4,5. As the tourist sector continues to develop, the combination of culture and tourism has become more prominent, leading to a greater focus on the concept of cultural tourism in academic discussions. In 1977, pioneering American scholars McIntosh and Gebert introduced the concept of “cultural tourism,” emphasizing culture’s comprehensive coverage of various dimensions within the tourism domain6. Subsequent scholarship by Bob Mckercher categorized “cultural tourism” into four distinct typologies: those derived from tourism, motivated by it, experiential, and actionable7. As culture and tourism intertwine, a confluence of elements and industry chains across related sectors emerges. Specifically, culture serves as the bedrock for tourist experiences, while tourism acts as a revenue source for cultural institutions8. This symbiotic relationship not only enhances tourism’s competitive edge but also propels its economic activities, thereby exerting a positive influence on overall tourism development9. Nonetheless, it is crucial to acknowledge the spatiotemporal disparities inherent in culture and the regional imbalances present in tourism development, both of which can impede culture’s role in propelling tourism forward10,11,12. However, despite the growing recognition of the significance of culture-tourism interplay, scholarly analysis of the nuanced characteristics defining the relationship between the cultural industry and the tourism sector remains relatively underexplored. Hence, there is a pressing need for comprehensive feature analysis to elucidate the intricacies of this symbiotic relationship and its implications for industry stakeholders.

Coupling, derived from physics, pertains to the dynamic interconnections among distinct systems13,14. The Coupling Coordination Degree model (CCDM) is a technique that measures the level of coupling to assess the strength of collaborative development15,16. It has been extensively utilized in study fields such as urban ecology17,18, low-carbon development19, and tourism20.

The Sustainable Development Goals (SDGs) adopted by the United Nations in 2015 provided a comprehensive framework for global development. Among them, SDG 8 emphasizes achieving decent work and economic growth through promoting the sustainable development of various industries. The prosperous development of the cultural and tourism industries can create a large number of employment opportunities, ranging from cultural and creative talents to tourism service personnel, covering multiple levels, which not only drives economic growth but also improves the quality of employment. SDG 11 is dedicated to building sustainable cities and communities. The cultural tourism industry can enhance the cultural charm and tourism attractiveness of cities and communities, drive infrastructure construction and environmental improvement, and promote the enhancement of community cohesion, thus realizing the sustainable development of cities and communities. SDG 12 focuses on responsible consumption and production. In the cultural tourism field, this means guiding tourists to make sustainable consumption, such as choosing environmentally friendly tourism products, and at the same time promoting cultural tourism enterprises to adopt sustainable production models to reduce resource waste and achieve sustainable development of the industry.

This research focuses on the coupling coordination and spatio-temporal dynamic evolution of the Japanese cultural and tourism industries. Japan is famous for its rich historical and cultural heritages and developed tourism industry. In 2019, the contribution rate of the tourism industry to its GDP reached 7.3%. However, the current theoretical research and quantitative assessment of the mutual relationship between the cultural and tourism industries still need to be further deepened. In view of this, this study constructs an evaluation index system and uses methods such as the coupling coordination degree model, kernel density analysis, and clustering analysis to deeply explore the comprehensive development levels, coupling coordination relationships, and spatio-temporal evolution laws of the cultural and tourism industries in Japan’s 46 prefectures from 2009 to 2019, aiming to provide a scientific basis for the sustainable development of the Japanese cultural tourism industry, and also provide references for other countries and regions in the research and practice of the cultural tourism industry, facilitating the healthy development of the global cultural tourism industry under the framework of achieving the SDGs.

Literature review

The research report by the United Nations World Tourism Organization (UNWTO) unequivocally asserts that a substantial 37% of global tourism activities are intricately linked to cultural elements, with the number of cultural tourists witnessing a notable annual growth rate of 15%. This pronounced trend not only underscores the profound interconnection between culture and tourism but also underscores the urgency and inevitability of the convergence and development of these two pivotal industries21. Within academic discourse, the relationship between culture and tourism has been extensively scrutinized, leading to a consensus on their mutual influence and causality in development22,23. The UNWTO book “Tourism and Culture Synergies” in 2018 emphasised the importance of the connections between the cultural and tourism industries. It explained how these connections play a crucial role in integrating culture and tourism.

Cultural-tourism integration is the process of combining the cultural and tourism industries to promote the sharing of resources, mutual promotion, and the achievement of common goals24,25,26. Rooted in the disparities between culture and tourism and their intersecting resources, attributes, functions, services, and stakeholders, this integration process positions culture as the essence of tourism and tourism as the conduit of culture27. The infusion of vitality into tourism by the cultural industry significantly enriches the content and cultural essence of tourism products, while the development of tourism injects fresh impetus into the exploration and innovation of cultural resources, fostering ongoing development and innovation within the culture industry28. Thus, culture-tourist integration is a mutually beneficial partnership that promotes close integration and reciprocal progress. It plays a crucial role in driving the transformation and improvement of both the culture and tourism industries towards high-quality development29,30.

The industrial perspective has become prevalent in scholarly discussions on the development of the culture and tourism industry’s linking coordination31. Evolving from early studies focused on simple relationships to contemporary inquiries into industrial convergence and coupling coordination, research emphasis has shifted towards exploring how these industries mutually propel and harmonize their development trajectories. Although there is limited literature specifically discussing the combined growth of the cultural and tourism industry, the idea of coupling coordination development adequately captures their inherent interconnectedness.

The synergistic effects and mechanisms between culture and tourism have emerged as central themes in research on cultural-tourism integration32. Various dimensions of culture, including spiritual, institutional, and material aspects, permeate tourism activities, imbuing them with profound cultural significance. Concurrently, tourism exerts a profound influence on the production, dissemination, and consumption of culture across temporal and spatial dimensions33,34. As cultural-tourism integration deepens, this field has emerged as a burgeoning area of inquiry within global tourism research. The significant growth of the cultural and tourist industry provides substantial empirical evidence for academic research and establishes a strong basis for the future direction of integrating culture and tourism.

The relationship between culture and tourism has long been a focal point of academic scrutiny35. Tourism, as a manifestation of human activity, is intricately intertwined with culture in practice36. Culture pervades the subjects, objects, and mediums of tourism, constituting a fundamental aspect of the tourism experience37. Tourist destinations often boast rich and diverse cultural heritage, historical legacies, and artistic expressions, serving as magnets for tourists worldwide38,39. Concurrently, tourism serves as a catalyst for cultural development, facilitating interactions between participants and cultural production processes across time and space. By promoting the preservation, transmission, and consumption of cultural heritage, tourism fosters the growth of cultural creativity and innovation40. The tourism-driven characteristics of culture underscore the role of tourism as a conduit for cultural exchange and interaction. Consequently, a thorough examination of the connection between the cultural and tourism sectors has significant implications for promoting the combined development of culture and tourism and supporting the long-term prosperity of both businesses.

Study area and data sources

Study area

Japan spans approximately 378,000 square kilometers and is composed of 47 prefectures. Renowned for its rich historical and cultural heritage, Japan boasts distinctive ethnic cultural characteristics, with a tally of 20 UNESCO World Heritage Sites recorded as of 2021. Concurrently, Japan’s tourism sector has flourished, evidenced by data from the Japan National Tourism Organization indicating that tourism contributed 7.3% to the nation’s GDP in 2019, cementing its status as a pivotal industry. Against the backdrop of cultural-tourism integration, Japan’s animation, cuisine, festivals, and other cultural facets have seamlessly intertwined with tourism, presenting a compelling paradigm for the synchronized advancement of Japan’s cultural and tourism sectors. Against this backdrop, considering the availability and integrity of data, this study examined the development of the cultural and tourism industries in 46 prefectures (excluding Tottori Prefecture) over a period of 11 years in order to clarify relevant insights. Figure 1 is overview of the research area.

Fig. 1
figure 1

Geographical location of the study area.

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Data sources

The COVID-19 pandemic in 2020 has brought an unprecedented impact to the global tourism industry, causing tourism activities around the world to come to a standstill and the tourism industry as a whole to be in trouble41,42. Based on this, this study investigated panel data in Japan from 2009 to 2019. The primary source of data for this study is derived from the official data center platforms listed below: Ministry of Land, Infrastructure, Transport and Tourism (https://www.mlit.go.jp/), Cabinet Office (https://www.cao.go.jp/), Japan Travel Agents Associatio (https://www.jata-net.or.jp/), Japan National Tourism Organization (JNTO) (https://www.jnto.go.jp/), Ministry of Health, Labor and Welfare (https://www.mhlw.go.jp/index.html), Agency for Cultural Affairs (https://www.bunka.go.jp/) and Japan in e-Stat statistics (https://www.e-stat.go.jp/). During the data collection process, this study also communicated with relevant departments via email. Linear interpolation was employed to fill in the missing data, which was present in a limited quantity.

Methods

This study uses the following methods and steps to scientifically measure and evaluate the degree of coupling and coordination between the cultural industry and tourism industry in each province in Japan. The main content of the research method core is shown in Fig. 2.

Fig. 2
figure 2

Evaluation framework.

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The construction of indicator system

In order to accurately assess the comprehensive development level of Japan’s cultural and tourism industry, this paper constructs an evaluation index system for both industries, embodying principles of scientific rigor, representativeness, comprehensiveness, and operability. The evaluation index system is based on previous research by Liu43. Please refer to Table 1 for detailed indicators:

Table 1 CI and TI indicator system.
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Entropy weight method

The entropy weight method, which utilizes information entropy, provides an unbiased approach to assigning weights50,51. It determines the weights by assessing the dispersion, or variability, of each evaluation indicator52. A higher dispersion implies greater information contribution from the indicator, resulting in a more significant impact on the evaluation system and consequently a higher weight allocation53. This method is widely used in fields such as multi-attribute decision-making and system evaluation.

Positive index (larger value for a useful parameter):

$${X_{{\text{ij}}}}=\frac{{{x_{ij}} - \hbox{min} \left\{ {{x_j}} \right\}}}{{\hbox{max} \left\{ {{x_j}} \right\} - \hbox{min} \left\{ {{x_j}} \right\}}}$$

Negative index (smaller value for a useful parameter):

$${X_{{\text{ij}}}}=\frac{{\hbox{max} \left\{ {{x_j}} \right\} - {x_{ij}}}}{{\hbox{max} \left\{ {{x_j}} \right\} - \hbox{min} \left\{ {{x_j}} \right\}}}$$

where Xij is the dimensionless value of the j index in the i-th year; xij is the initial value of the j-th index in the i-th year; max { xj } is the maximum value of the j-th index; min { xj } is the minimum value of the index of the j-th index item. After undergoing dimensionless processing, all index values fall inside the 0 to 1 range. It should be noted that the value range of all index values after dimensionless processing is between 0 and 1.

Coupling coordination degree model

The coupling coordination degree model is a complete instrument utilized for analyzing the degree of coordinated development of phenomena54,55. The main focus is to examine the connections, reciprocal effects, and level of coordination between two or more systems in order to evaluate the progress of coupling coordination development between them14,56. Table 2 shows the classification of different levels of coupling coordination:

$$c=\sqrt {\left[ {1 - \sqrt {{{\left( {{P_E} - {P_T}} \right)}^2}} } \right] \times \frac{{{P_T}}}{{{P_E}}}} =\sqrt {\left[ {1 - \left( {{P_E} - {P_T}} \right)} \right] \times \frac{{{P_T}}}{{{P_E}}}}$$
$$D\left( {{P_T}} \right.,\left. {{P_E}} \right)=\sqrt {C \times T}$$
$$T=\alpha {P_T}+\beta {P_E}$$

where T is the composite indicator measuring the level of development in the tourism industry and the ecological environment system; D is the composite system coordination index; α and β are the unidentified weights of the system, indicating the relative contributions of the tourism economy and natural environment to the composite system. The paper takes α = β = 0.5.To examine coupling coordination more simply and logically, In order to categorize the level of coupling coordination between tourist industry and ecological environment systems, the paper makes use of the mean distribution function, a 10-point technique54, as shown in Table 2.

Table 2 Table presenting the classification of coupling coordination degree.
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Membership degree model

The membership degree model is a mathematical model based on fuzzy set theory, used to describe and quantify the degree to which an element or entity belongs to a fuzzy set58. This study employs the membership degree model to address the challenge of abrupt changes in boundary values, which is a common issue in complex systems analysis. In other words, the role of the membership degree model in this study is to further refine and conduct in-depth analysis on the results calculated by the coupling coordination degree model, so as to depict the mutual relationship and coordination state between the cultural and tourism industries more precisely. By leveraging fuzzy logic principles, the model captures the gradual transitions between different states or categories, providing a more nuanced understanding of system behavior43. The calculation is shown below and the principle is shown in Fig. 3.

When \(n=1,\)

$$\begin {aligned} {{S}_{n}}\left( x \right)=\left\{ \begin{matrix}1, \\1-10x, \\0, \\\end{matrix} \right.\begin{matrix} x\le \frac{n-2}{10} \\0<x<0.1 \\ x\ge 0.1 \\\end{matrix}\end {aligned}$$

When \(2 \leqslant n \leqslant 9,\)

$$\begin {aligned} {{S}_{n}}\left( x \right)=\left\{ \begin{matrix}0, \\10x-n+2, \\ n-10x, \\0, \\\end{matrix} \right.\begin{matrix} x\le \frac{n-2}{10} \\\frac{n-2}{10}<x\le \frac{n-1}{10} \\\frac{n-1}{10}<x<\frac{n}{10} \\ x\ge \frac{n}{10} \\\end{matrix}\end {aligned}$$

When \(n=10,\)

$$\begin {aligned} {{S}_{n}}\left( x \right)=\left\{ \begin{matrix}0, \\10x-9, \\1, \\\end{matrix} \right.\begin{matrix} x\le 0.9 \\0.9<x<1 \\ x\ge 1 \\\end{matrix}\end {aligned}$$
Fig. 3
figure 3

Membership degree model.

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Result and analysis

Comprehensive development level of cultural industry and tourism industry

Based on Fig. 4A, it can be observed that the cultural index of the 46 prefectures in Japan, excluding Tottori, showed an overall upward trend from 2009 to 2019. This indicates that during this eleven-year period, the level of development in Japan’s cultural industry has experienced a certain degree of improvement, with a relatively stable trend. The cultural index of most prefectures is concentrated between 0.1 and 0.3, suggesting that the cultural development level in most prefectures is relatively low and fairly consistent. However, the cultural indices of Tokyo and Osaka have consistently remained above 0.75, indicating a significant gap compared to most prefectures. Furthermore, over time, the gap in cultural indices between Tokyo and Osaka has gradually narrowed, with Osaka’s overall growth rate in cultural industry development surpassing that of Tokyo. Although the growth rate of the cultural industry in Tokyo is relatively slower compared to Osaka, the cultural index continues to approach 1, maintaining a relatively high level of development over the eleven-year period. Additionally, the gap in cultural indices between the remaining prefectures and Tokyo and Osaka is also gradually narrowing but still remains relatively large. In terms of the average development level, the average cultural index fluctuates between 0.201 and 0.332 annually over the eleven-year period, with a total average cultural index of 0.271. Overall, with the passage of time, the level of development in Japan’s cultural industry is continuously improving, but overall, the development level is uneven, characterized by a few high, a minority moderate, and the majority low situations.

Fig. 4
figure 4

Comprehensive development level of CI and TI from 2009 to 2019.

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According to Fig. 4B, the overall tourism index in Japan demonstrated an upward trend from 2009 to 2019, indicating a general enhancement in Japan’s tourism sector. Most prefectures exhibited tourism indices concentrated below 0.25, suggesting a relatively modest level of tourism development, which was consistent across these regions. Conversely, Tokyo and Osaka consistently maintained tourism indices above 0.6, distinguishing them as notable regions with a substantial margin compared to most prefectures.

Over the eleven-year period, most prefectures witnessed an overall upward trajectory in their tourism indices. However, Tokyo and Osaka experienced fluctuating trends. Notably, from 2009 to 2018, the tourism indices showed a progressive incline, with a notable surge observed between 2010 and 2011. Yet, from 2018 to 2019, a declining trend was noted, with moderate growth in other years. Nevertheless, the gap between Tokyo and Osaka’s tourism indices remained relatively stable. On average, annual tourism index varied between 0.185 and 0.307 during the course of eleven years, with an overall average tourism index of 0.25. This indicates that the general level of development in Japan’s tourist industry is moderate.

In summary, during the period from 2009 to 2019, both Japan’s cultural and tourism sectors experienced some advancements. Tokyo and Osaka showcased relatively high levels of development in both cultural and tourism domains, while most other regions demonstrated comparable yet relatively low levels of development. The cultural and tourism industry exhibited distinct levels of development, with most regions scoring poorly, indicating an overall imbalance in growth.

Analysis of coupling coordination degree between culture and tourism industry

In Fig. 5, In the Japan region, the coupling coordination degree between culture and tourism increased from 0.317 to 0.378, albeit with a little increase, and the coupling coordination degree between culture and tourism is generally slightly unbalanced. This indicates that Japan still has a long way to go in terms of coordinating culture and tourism. When analyzed spatially, the coupling coordination degree in Japan is substantially stronger in the region of the area traversed by the 35°N latitude line, with Tokyo and Osaka standing out. Conversely, areas near the 32nd and 39th parallel north latitude lines exhibit lower coupling coordination degree, implying a less synchronized link between the cultur and tourism industry.

Fig. 5
figure 5

Spatiotemporal evolution of CI and TI coupling coordination degree.

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Furthermore, the Kanto and Kinki regions, centered around Tokyo and Osaka respectively, demonstrate elevated levels of coupling coordination degree, reflecting their relatively advanced development in both cultural and tourism sectors. Similarly, Hokkaido, a popular tourist destination, has relatively high levels of coupling coordination between its culture and tourism industry. In contrast, the Chubu region presents a more moderate level of coupling coordination degree, with development oscillating between mild imbalance and marginal coordination. However, Japan’s Tohoku, Chugoku, Kyushu, and Shikoku regions are less coordinated in terms of regional coupling, and are in the range between serious imbalance and moderate imbalance. Overall, with the exception of Hokkaido, Japan’s cultural and tourism industry demonstrate a pattern of moderate-to-high coordination in central regions, while peripheral areas exhibit lower levels of coordination, highlighting significant regional disparities.

Analysed from the perspective of time, from 2009 to 2019, the degree of coordination between culture and tourism in Japan increased year after year. The level of coupling coordination between culture and tourism in Miyazaki, Iwate, Fukui, Yamanashi, and Tochigi has increased from 2009 to 2012, it is still at the level of imbalance. However, the coupling coordination degree between culture and tourism in Nara has transitioned from a moderate imbalance to a serious imbalance. From 2012 to 2016, the coupling coordination degree between culture and tourism in regions experienced a similar improvement such as Kumamoto, Kagoshima, Kagawa, and Nara, as well as Mie, Miyagi, and Nagano, from serious imbalance to moderate imbalance, and then from moderate imbalance to mild imbalance. Despite remaining in an imbalanced state, there is an overall positive trend observed during this period. From 2016 to 2019, the coupling coordination degree between culture and tourism in Tokushima has transitioned from a state of severe imbalance to a state of moderate imbalance. The coupling coordination degree in Okayama and Shiga has transitioned from a moderate imbalance to a mild imbalance. The level of coupling coordination in Kyoto has transitioned from a mild imbalance to a state of near imbalance. In contrast, the other prefectures remained relatively stable over the duration of the study. Generally speaking, over the course of 11 years, the overall coupling coordination degree in Japan has been steadily increasing. However, the rate of increase has been very sluggish and the magnitude of the increase has been quite modest. Among them, Tokyo and Osaka have consistently maintained a relatively high level of coupling coordination, especially Tokyo and Osaka, which have a high level of coupling coordination between culture and tourism. It should not be overlooked that there are still 19 prefectures that have not changed significantly over the eleven-year period.

Test of the coupling and coordination degree between cultural industry and tourism industry

Kernel density analysis

This research used Kernel Density Analysis in ArcGIS to determine the spatial distribution density of the coupling coordination degree between Japan’s culture and tourism industry in order to evaluate their development state, as shown in Fig. 6. The resulting map reveals distinct patterns: notably, in the Tokyo and Osaka regions, colors are deeper, indicating higher kernel density values, suggesting a more robust level of coordination between cultural and tourism sectors. Conversely, regions like Tohoku, Kyushu, and Shikoku exhibit lighter colors, signifying lower kernel density values and consequently poorer coordinated development between these industries. Over time, discernible changes in color depth are observed, particularly in the Kyushu region, where darker colors expand gradually. This indicates gradual enhancements in the synchronized advancement of the culture and tourism industry in Kyushu throughout time. Overall, the color distribution presents a distinct pattern: darker shades are concentrated in the middle, while lighter shades predominate on the sides. This indicate that there is a greater degree of coupling coordination development in core locations and a lower degree of coordination development in peripheral places. Notably, Tokyo and Osaka are particularly notable for their strong collaboration between the culture and tourism industry. Furthermore, as time progresses, areas transitioning from lighter to darker shades continue to increase, indicating an overall positive trend in the coupling coordination degree between culture and tourism industries. This suggests enhancing coordination and synergy between these sectors is yielding positive results, contributing to their overall development.

Fig. 6
figure 6

Spatiotemporal distribution of nuclear density of CI and TI coupling coordination degree.

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Cluster difference analysis

Clustering and outlier analysis in ArcGIS are utilized to investigate the level of coupling coordination between the culture and tourism industry, as well as the interrelationship between different regions in Japan. According to the results in Fig. 7, Japan presents four main types of clustering, namely high - high clustering, high–low clustering, low–high clustering and low–low clustering. From 2009 to 2012, certain prefectures in the Chugoku region transitioned from being a cluster with high–low characteristics to a cluster with low-low characteristics. This indicates that the disparity between this particular area and its neighboring regions is gradually diminishing, and that the level of coordination and development between culture and tourism is similar. In the Kanto region, there is a transition from a densely concentrated area of high coupling coordination between culture and tourism to a sparsely concentrated area of high coupling coordination. This suggests that the development of coordination between culture and tourism in this region is progressing at a slower rate compared to the surrounding regions. From 2012 to 2016, certain prefectures in the Kanto region transitioned from having a low concentration of cultural and tourist development to having a high concentration. This suggests that the level of cooperation between culture and tourism in this area is steadily improving and becoming more comparable to adjacent regions. From 2016 to 2019, some prefectures in the Kyushu region and the Kanto region shifted to non-significant clustering. In addition, the Hokkaido region shifted from insignificant clustering to high - low clustering. This inferred that the degree of integration and synchronization between culture and tourism in the Hokkaido region has progressively risen over the years, creating a gap with the neighboring regions. Typically, there is a significant concentration of high-high clustering in the Kanto region, while the low-low clustering is primarily concentrated in the Chugoku, Kyushu, and Shikoku regions. The clustering results for the Tohoku and Chubu regions are not clearly evident. This indicates that areas with a high level of coupling coordination development between culture and tourism, while promoting their own coupling coordination development between culture and tourism, have a certain radiant effect on the surrounding areas, which is primarily concentrated in the Kanto region. Obviously, this demonstrates that the Kanto and Hokkaido areas have a high level of coupling coordination development between culture and tourism, whereas the Kyushu, Shikoku, and Chugoku regions have a low level of coupling coordination development between culture and tourism.

Fig. 7
figure 7

Cluster classification diagram based on the coupling coordination degree between CI and TI.

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Discussion

Comprehensive development level of cultural industry and tourism industry

“Comprehensive development level of cultural industry andtourism industry” focuses on the development levels of Japan’s culture and tourism industry. Firstly, both the cultural index and the tourism index of Tokyo and Osaka maintained relatively high values from 2009 to 2019, while other prefectures showed significant gaps compared to them. The primary reason is that Tokyo, as Japan’s largest city and a center for politics, economics, and culture, possesses rich historical and cultural heritage as well as abundant tourism resources. It is one of the most culturally influential cities in the world and is often hailed as the most charming city in the world by magazines such as the British Monocle. Likewise, Osaka, Japan’s second largest city, is an important arts and cultural center with numerous historical sites and cultural heritage. Landmark buildings such as Osaka Castle, Tsutenkaku Tower, and Tennoji Temple are important carriers of Osaka’s cultural tourism resources. It is worth pointing out that there are certain differences in the cultural tourism index between Tokyo and Osaka. The main reason is that Tokyo has been an administrative center since the Edo period and has maintained a leading position in economic development and urban construction. It should be noted that under the aftershocks of the 2009 global financial crisis, the cultural and tourism industries in Tokyo and Osaka were also impacted59,60. Enterprises were cautious about investment, and some cultural and tourism projects suffered from a shortage of funds61. For example, the scales of some large-scale cultural performances were limited due to reduced sponsorship, and the market demand for high-end tourism projects declined. However, thanks to their diversified economies and solid industrial structures, they still maintained a relatively high level on the whole, although the growth rate slowed down.

Moreover, Tokyo leans towards modernization and internationalization, boasting a well-developed transportation system. On the other hand, Osaka emphasizes historical culture and local characteristics, with a transportation system that, while sufficient for tourists’ travel needs, is relatively simpler. Furthermore, the decline in the tourism indices of Tokyo and Osaka in 2018–2019 can be attributed to the deterioration of Japan-Korea relations during this period. According to surveys conducted by the Osaka Tourism Bureau on five Korean travel agencies, the number of group tourists visiting Osaka from South Korea decreased by 20–80% from August to September compared to the same period in 2018. However, over the past eleven years, the overall development levels of the culture and tourism industry in other regions have increased. This is because during this period, the Japanese government relaxed tourism visa requirements for foreign visitors and provided policy support and guarantees62,63.

Analysis of coupling coordination degree between culture and tourism industries

The complete growth in coupling coordination development between culture and tourism in Japan from 2009 to 2019 is owing to the fact that both the level of cultural development and the level of tourist development have advanced to some extent during this time. This is mainly due to the quantitative easing policy system of “Abe Economics”, which has stimulated tourism consumption in Japan. The quantitative easing policy of “Abenomics” led to the depreciation of the Japanese yen, strengthening the price competitiveness of Japanese tourism products in the international market, attracting more overseas tourists and stimulating the growth of the tourism consumption market64,65. Meanwhile, the government’s investment in infrastructure construction under its fiscal policy benefited some tourism infrastructure to a certain extent, improving the tourist experience and indirectly promoting the development of the tourism industry. Although the Great East Japan Earthquake occurred in 2011, the government’s reconstruction work and tourism revitalization policies facilitated the recovery and development of the cultural and tourism industries in the disaster-stricken areas and their surrounding regions, and also promoted the integration and innovation of culture and tourism, such as the development of earthquake-themed tourist routes66.

Among them, Tokyo and Osaka are better coupling coordination degree, mainly because of their developed economies and rich cultural and tourism resources, as well as more perfect tourism infrastructure and service system, with higher visibility and reputation. From the perspective of international comparison, compared with global top tourist cities like New York and Paris, Tokyo and Osaka still have room for improvement in terms of the in-depth development and integrated marketing of cultural tourism resources. For example, New York has closely combined cultural arts with tourism consumption by creating cultural brands such as Broadway musicals, attracting a large number of tourists from all over the world. Paris, with world-famous cultural attractions like the Louvre as the core, has built a sophisticated cultural tourism ecosystem, enabling tourists to conveniently enjoy high-quality cultural tourism experiences in the city. Tokyo and Osaka can draw on the successful experiences of these international metropolises, further tap into their own cultural potentials, optimize the supply of tourism services, and enhance the international competitiveness of their cultural tourism industries.

However, the coupling coordination degree in regions such as Kyushu and Shikoku in Japan is relatively low. Compared with developed regions like Kanto, they are geographically remote and their economic development is relatively backward, which to some extent restricts the development of the cultural tourism industry. Although from the domestic perspective in Japan, the transportation convenience in these regions is not as good as that in Tokyo and Osaka, compared with remote regions in some developing countries, their infrastructure level still has certain advantages. However, in terms of the refined construction of tourism infrastructure and the professional improvement of service quality, there is still an obvious gap compared with countries renowned for high-quality tourism such as Switzerland and Austria. For example, in the small towns in the Swiss Alps, although they are located in remote areas, they have attracted a large number of international tourists by virtue of their precisely positioned outdoor sports tourism products and world-class tourism service facilities. The rural areas in Austria have created highly attractive rural cultural tourism destinations through a complete rural tourism traffic sign system, comfortable accommodation facilities and rich folk cultural experience activities. Regions such as Kyushu and Shikoku can learn from the experiences of these countries, strengthen regional cooperation, integrate scattered tourism resources, improve tourism signs and supporting facilities, enhance the professional qualities of tourism service personnel, and deeply explore and promote local characteristic cultural tourism resources, so as to improve the coupling coordination degree and attractiveness of the cultural tourism industry.

Hokkaido has a relatively high coupling coordination degree. It benefits from fully utilizing its unique local natural and cultural resources and has successfully created a series of tourism products with strong local characteristics, such as the Sapporo Snow Festival and the Asahikawa Ice Festival, enabling tourists to deeply experience the charm of Hokkaido’s traditional culture. Compared with Quebec Province in Canada, both regions possess rich ice and snow resources and unique regional cultures. Hokkaido can draw on the experience of Quebec Province to launch special projects such as ice and snow hotel accommodations and ice and snow art creation workshops, and enrich tourists’ cultural experiences through cultural performances and traditional handicraft displays. By further expanding the diversity of tourism products, enhancing the display and dissemination effects of cultural connotations, and strengthening the comprehensive competitiveness of the cultural tourism industry.

Test of the coupling and coordination degree between cultural industry and tourism industry

Through kernel density and cluster analysis, on the whole, there is no significant difference in the development layout of the coordinated development level of Japanese culture and tourism, mainly with Tokyo and Osaka as the core regions. However, it is worth noting that in the Kyushu region, the color depth has changed significantly over time and the scope has gradually expanded. The main reason is that the opening of the Shinkansen running through Kyushu in 2011 brought vitality to the region’s development67. Kumamoto Prefecture took this opportunity to create the “Kumamon” IP and improve the “Kumamon +” industrial chain, successfully attracting a large number of tourists and driving the development of local and Kyushu tourism, enabling it to take important steps in the coordinated development process of culture and tourism and showing a positive trend in kernel density and cluster analysis.

In addition, from 2012 to 2016, the Hokkaido region changed from an insignificant cluster to a high-low cluster. This indicates that during this period, the growth rate of the coordinated development level of culture and tourism in the Hokkaido region increased faster than that of the surrounding regions. This achievement is closely related to the Basic Plan for the Revitalization of Hokkaido Culture implemented by the Hokkaido government in 2012. The Basic Plan for the Revitalization of Hokkaido Culture has clear and comprehensive goals, which are committed to promoting the in-depth integration and coordinated development of the cultural and tourism industries and enhancing the overall strength of regional cultural tourism67.

For example, in terms of the protection and development of cultural resources, resources have been invested to systematically sort out and restore the traditional buildings, sacrificial rituals and other aspects of the unique local cultural heritages like those of the Ainu people, and cultural exhibition venues have been built, allowing tourists to appreciate their cultural charm and enriching the connotations of cultural tourism. In the aspect of cultural industry cultivation, the government has launched a number of preferential measures, providing financial and tax support for cultural and creative projects, which has stimulated the vitality of cultural enterprises and creative talents and given birth to a large number of cultural products with Hokkaido characteristics, such as handicrafts and literary works. These products are closely linked to tourism, being exhibited and sold in scenic spots or cultural activities being carried out, which has promoted the interaction between culture and tourism economies and injected impetus into the development of the industries. In terms of the construction of tourism infrastructure, the government has focused on optimizing the transportation network to improve the accessibility of scenic spots, while improving facilities such as tourist service centers, parking lots, catering and accommodation in the scenic spots, creating a good experience for tourists and building a solid hardware support system. In terms of talent cultivation, professional courses and training programs have been jointly opened with local educational institutions to cultivate compound talents for cultural and tourism operations. Meanwhile, external experience and talents have been actively introduced to provide guarantees for the continuous upgrading of the industries and comprehensively help the Hokkaido cultural tourism industry grow and develop.

To sum up, the Basic Plan for the Revitalization of Hokkaido Culture has made efforts from multiple dimensions and comprehensively promoted the coordinated development of the cultural and tourism industries, strongly proving the close causal relationship between this policy and the research results, providing a solid support for the prosperity of the Hokkaido cultural tourism industry and also offering useful references for the cultural tourism development of other regions in Japan.

Conclusion

Culture and tourism have played an important part in Japan’s economic development, social improvement, and international image construction. For this reason, this study thoroughly examines the development level of the cultural and tourism industries in 46 Japanese prefectures from 2009 to 2019, and incorporates the membership degree model into the coupling coordination degree model to conduct an accurate quantitative evaluation of the degree of coupling coordination. Kernel density and clustered outlier analysis were employed to examine the progress of coupling coordination degree between culture and tourism in 46 Japanese prefectures. The primary conclusions of this research are as follows:

  1. (1)

    Over time, the growth rate of the level of coupling coordination between culture and tourism in Japan has been relatively stable but remains mostly unbalanced. From 2009 to 2019, the degree of coupling coordination between the culture and tourism industry in Japan has steadily risen, with the exception of Tottori. Tokyo and Osaka surpass other Japan’s prefectures in the advancement of cultural and tourism industry. Japan should further explore these cultural resources, integrate cultural elements into tourism products and services, and create tourism brands with cultural connotations and characteristics. For example, the Kanda Festival, the Yodogawa Fireworks Festival, and the Sapporo Snow Festival. Facilitate the advancement of culture and tourism in Japan and infuse fresh vitality into the growth of every region.

  2. (2)

    From a spatial point of view, with the exception of Hokkaido, Japan’s culture and tourism industry generally exhibits a pattern of high coupling coordination in the middle and poor coordination on both sides. In other words, the development of Japan’s culture and tourism industry mainly revolves around Tokyo and Osaka. Japan should vigorously promote the improvement of transport and other infrastructures, especially increasing the number of trains as well as bus lines to improve regional accessibility. It should also further enhance tourism services, improve tourism facilities, and enrich and optimize tourism routes with local cultural resources. It is important to prioritize strengthening the policy orientation to encourage the coupling coordination of culture and tourism in other regions.

  3. (3)

    Furthermore, this study discovered that regions with commendable economic advancement, such as Tokyo and Osaka, exhibit notable progress in their culture and tourism sectors, which in turn positively influences the surrounding communities. Currently, the amount of coupling coordination development in Japan’s culture and tourism industry is slightly imbalanced, resulting in inadequate coordination between culture and tourism. Hence, it is imperative to comprehend the degree of interconnection and synchronization between the growth of culture and the tourism industry, and to facilitate the advancement of this interconnection and synchronization.

This research also has certain limitations. It lacks the latest data on the progress of the Japanese cultural tourism industry after 2019, especially after being affected by the public health crisis. Some regions in Japan failed to release relevant data on the tourism industry in a timely manner. As a result, we are unable to infer whether the cultural tourism industry has been developing in a more positive direction in recent times based on the existing conclusions, and this is an important issue. Meanwhile, due to limitations in data acquisition, what we have explored is the coupling and coordination status of culture and tourism at the provincial level in Japan, lacking exploration from more microscopic perspectives such as at the county level or in rural areas. This has led to the policy suggestions we put forward being more applicable to the macro level rather than specific towns or villages.

Therefore, in future research, exploring the linkage and synchronization of the cultural tourism industry in the face of the public health crisis is an area worthy of further study. Moreover, we might consider collecting data from a more microscopic perspective (such as data from towns or villages) to depict more specific coordination changes and put forward more targeted policy suggestions.