Izanami is one of the two creation deities of Japanese myth, along with her husband, Izanagi. After they dipped a divine spear into the ocean to create the islands of Japan, Izanami began to give birth to other gods, but ultimately met her end when she died giving birth to Kagutsuchi, god of fire. Enraged, Izanagi killed Kagutsuchi and from his blood and remains were created even more gods.
After Izanami was buried, the grief-stricken Izanagi ventured to Yomi, or the underworld, to see if his wife could be saved. When he reached there however, he found that she had already begun to rot. Horrified at her sight, Izanagi fled from Yomi with Izanami chasing after him. After reaching the land of the living once more, Izanagi closed off the entrance to Yomi. Izanami cursed at Izanagi, saying that if he left her, she would kill 1,000 people every day; in reply, Izanagi asserted that he would daily bring life to 1,500.
In Digital Devil Story: Megami Tensei, the first Megami Tensei game released, it is revealed that the heroine Yumiko is actually the reincarnation of Izanami.
From this is derived the title "Megami Tensei", which means "goddess's reincarnation."
In the "true" ending path of Persona 4, it is revealed that the goddess Izanami was ultimately responsible for the game's events. Disguised as a human, she approaches Yu Narukami near the start of the game in the guise of a gas station attendant and, by shaking his hand, granted him the ability to enter the TV World, just as she had done for both Taro Namatame and Tohru Adachi. She selected these three individuals based on aspects they represented in the hopes that she would learn humanity's true desire; she believed that humanity wished to give up their pain by becoming Shadows, and felt that this would show through in her little scenario. Then she simply stood back and watched as all three engaged each other in a battle of wits over the course of the murder investigation. In March of 2012, the day before Yu is to return to the city, he receives a letter from Adachi, prodding him and his friends to continue the investigation they previously thought closed with the defeat of Ameno-Sagiri and Adachi's arrest. After receiving the Orb of Sight from Igor and performing some detective work, Yu confronts the gas station attendant and learns of her true identity.
Izanami is both impressed and taken aback by Yu's continued pursuit of the whole truth; she never intended for him or anyone else to learn of her involvement in the events that had transpired over the past year. She challenges him and his friends to a final battle, and then retreats to the TV World to await him. Although as a goddess, she could never truly be killed, Yu and friends manage to defeat the combat form she created, and she decides that this indicates that humanity does not wish for destruction after all. With this, Izanami leaves Inaba, the threat of the fog truly comes to an end, and the TV World transforms into a natural wonderland, symbolizing mankind's hope for the future.