Yomi appears in the Kojiki and Nihon Shoki, Japan's two oldest chronicles, as the destination of Izanami, the creator goddess who dies after giving birth to the fire kami Kagutsuchi and descends to the underworld. Her husband Izanagi, grieving, follows her into Yomi and finds her in darkness, asking her to return with him to the world of the living. Izanami tells him she has already eaten the food of Yomi and can no longer leave, but asks him to wait while she consults the deities of the underworld, warning him not to look at her in the meantime.
Izanagi breaks the promise, lighting a comb to see her, and discovers her body rotting and infested, crawling with maggots and accompanied by thunder deities born from her decay. Horrified, he flees, and an enraged Izanami, humiliated at being seen in this state, sends the hideous hag of Yomi and an army of thunder deities and warriors after him. Izanagi escapes by sealing the pass between Yomi and the living world with a great boulder, and Izanami, trapped on the other side, vows to kill a thousand people a day from the land of the living in retaliation, to which Izanagi responds that he will cause fifteen hundred to be born each day, a bitter exchange that Shinto tradition reads as the origin of mortality itself.