The popular Japanese travel guide series, "Walk the Earth," finds great success in its domestic edition. The series, celebrated for its rich content that promotes cultural understanding in both global and local aspects, has seen increased sales in Japan, suggesting a growing interest in domestic travel. The precise cause of this success remains uncertain and presents an interesting question for publishers and tourism industry alike.

The popularity of the "Walk the Earth" domestic edition reflects Japan's focus on promoting local tourism and cultural awareness. With frequent collaborations between local governments and tourism authorities, travel guidebooks are not just consumer products, but become a part of larger initiatives to boost the economy and nurture a sense of national identity.

In the US or EU, comparable travel guide series such as "Lonely Planet" or "Rough Guides" also play a significant role in promoting tourism. However, the emphasis may be more on international rather than domestic travel, reflecting more diverse and multicultural environments in these regions.