Traditional Japanese cuisine (WASHOKU) was added to the UNESCO's Intangible Cultural Heritage list in 2013, resulting in more attention to WASHOKU in all over the world. In Japan, however, the WASHOKU culture seems to gradually disappear in our daily life. To maintain and heritage the WASHOKU culture, home dining and regional cuisine are important targets to be considered. Seasoning appears to be a key factor in establishing characteristics of each regional cuisine. Soy sauce, one of traditional seasonings, is especially important because soy sauce is frequently utilized throughout Japan to cook regional cuisine. Therefore, we first investigated its regional characteristics by using sensory analysis. As a result, we showed that as the region is far from the Tokyo metropolitan area, saltiness intensity of soy sauce tends to be low. We also examined the compatibility between soy sauce and local dishes. Furthermore, we found that using soy sauce in western dishes, the amount of salt could be reduced and the dish became more palatable. We hope that the registration of WASHOKU to UNESCO’s Intangible Cultural Heritage list become a good occasion to increase the opportunity to consider and talk more about soy sauce as an important WASHOKU constituent, to facilitate communication among people, and to strengthen the value of WASHOKU.