Who is the daughter of the dragon king and wife of Hoori?

Toyotama-hime is the daughter of the dragon king and the wife of Hoori in Japanese mythology.

Her father is Watatsumi, the sea deity who lives in an undersea palace. Hoori, also called Yamasachi, reaches Watatsumi’s realm while searching for a lost fishing hook belonging to his brother. Toyotama-hime meets him there, and her father arranges their marriage.

The couple later return to the human world, where Toyotama-hime gives birth to Ugayafukiaezu. She asks Hoori not to watch her during childbirth, but he breaks the promise and sees her in her animal form, described as a wani—possibly a crocodile or shark—or a dragon in one version. Ashamed, she returns to the sea.

A common mix-up is Toyotama-hime’s relationship to Tamayori-hime: Tamayori-hime is her younger sister, not her mother or daughter. Toyotama-hime is also the grandmother of Emperor Jimmu through Ugayafukiaezu.