Toyotamahime no Kami (Toyotama-hime) is a god (Shinto) appearing in volume one of "Kojiki" (The Records of Ancient Matters), and the mythology of Yamasachihiko and Umisachihiko. She is the daughter of sea god, Watatsumi (Watazumi).
She married Hoori (= Yamasachihiko), who was born between Tenson (the grandson of the sun goddess) Ninigi and Konohana no sakuya-bime, the daughter of Oyamatsumi, and gave birth to Ugayafukiaezu. At the time of delivery, she transformed into an Eight-fathom shark (Yahirowani) in the Kojiki and Arufumi (supplement volumes of explanatory notes in Nihonshoki) of Nihonshoki and dragon in the main text of Nihonshoki, and because Hori no Mikoto broke the promise and took a look, she returned to the land of Watatsumi no Kami. Ugayafukiaezu no Mikoto was brought up by her sister, Tamayori-hime, and later gave birth to Kamuyamatoiwarebiko no Mikoto (= Emperor Jinmu) with Tamayori-bime.
According to Takeo MATSUMURA (1884 - 1969), it was taboo to see a woman give birth in the form of her original province, because it reflected the folkways in which the period of monoimi (avoiding something regarding as ominous) when the woman worshiped a god from a different tribe from the god of the husband was jugon (purifying misfortune with charms) for the husband, and social sanction was imposed when this was violated. Transforming into a crocodile suggests that the people of the sea worshipped crocodiles as their totem, feathers of cormorant was used in the ubuya, a hut for a delivery of baby, as magic (a spell) for safe delivery ('Shaku Nihongi' (annotated text of the Nihon Shoki) 'Nihonki-sanso'), and Amenooshihito no Mikoto swept away a crab when the ubuya was built as a similar magic to celebrate the long life and good health of the newborn. The ubuya not being completely thatched was a childbirth folkway (Okinawa), the ubuya built on the seaside was associated with the demonstration of the spiritual power of the newborn using the mysterious power of water, the fact that the husband asked Toyotama-hime the name of the newborn can be traced back to the system when the mother had the naming rights as in the article of Emperor Suinin in 'Kojiki,' and when Toyotama-hime intercepted Unazaka and the traffic between land and sea came to an end, it was an outburst of a sense of strange land among the ancient Japanese, centered around the area of residence, similar to Yomotsu Hirasaka (the slope that leads to the land of the dead).