In the beginning, according to the Kojiki — Japan's oldest chronicle compiled in 712 CE — the heavens and earth were not yet separated. The world was a formless, drifting mass, like oil floating on water. Into this primordial state, two divine beings descended along the Heavenly Floating Bridge: Izanagi, "He Who Invites," and Izanami, "She Who Invites." Commanded by the heavenly deities to solidify the land, they stirred the ocean with a jeweled spear until it thickened into the first island, Onogoro. Descending to this island, they circled its central pillar and called out to one another, their union producing the islands of Japan and then a succession of kami — gods of wind, sea, fire, mountains, and rivers. The birth of the fire god Kagutsuchi cost Izanami her life, his flames burning her fatally as she labored. Izanagi's grief was enormous; he wept, and from his tears more deities were born. Then, refusing to accept the separation, he descended into the underworld Yomi to bring his beloved back.

The journey to Yomi and its aftermath is one of the most mythologically rich episodes in Japanese tradition. Izanagi found Izanami but was forbidden to look at her before she had sought permission from the underworld's rulers to leave. Unable to wait in the darkness, he broke his promise and lit a comb-tooth to see — and saw his wife in an advanced state of decomposition, surrounded by thunder demons. She, enraged and humiliated by his gaze, pursued him as he fled. Izanagi escaped by rolling a great boulder across the entrance to Yomi, and there, across that stone, the two divine creators spoke their last words: Izanami promising to kill a thousand people each day, Izanagi vowing to create fifteen hundred new lives in response. This exchange — death and birth locked in eternal negotiation — became the mythological explanation for mortality itself. Izanagi then purified himself in a river, and from that purification, washing off the pollution of death, three of Japan's most important deities were born: Amaterasu from his left eye, Tsukuyomi from his right, and Susanoo from his nose. The myth thus ties creation, love, death, grief, and renewal into a single continuous narrative — a cosmology that mirrors the deepest rhythms of existence.