In Japan, there are many regional legends and traditions associated with water, fish, and fantastic creatures inhabiting the sea. These legends go back many centuries; the first mentions of large fish are found already in the first Japanese poetic anthology Man’yōshū (8th century) and in the mythological and chronicle text Nihon Shoki (720). In different provinces, legends and traditions vary, some motifs are interpreted differently by folklorists, however. Evidently, we can talk about a single body of related texts, united not only by plots where the main characters are whales, dolphins, etc., but also by accompanying actions: matsuri festivals in honor of fish and fishing, ritual performance of magical texts, dancing, songs, cooking, making amulets, etc. The symbolism that unites the theme of fish and fishing in Chinese and Japanese culture is also obvious: wealth and prosperity, which is reflected not only in written monuments, but also in works of art. Whales, for example, are associated with numerous legends, traditions, and mythological motifs of local significance, ideas about these mammals as deities of the sea, to whom Shinto shrines are dedicated. Images of fish were part of offerings to the bride’s family due to the auspicious meaning of the item. It is noteworthy that the legends about the sea included famous literary and legendary characters and episodes from famous works of Japanese history and literature, such as Kojiki, Nihon Shoki, Man’yōshū, Heike Monogatari.