Izanami

The story of Izanami is a lot like the story of Orpheus going down in hell to retrieve his love (sorry, can't think of her name at the moment). Izanami dies, and Izanagi goes to hell to get her. Both men go down and both look back to their loves, eventually losing them because they looked back. It really makes you think. Anyway, after Izanagi left and sealed the portal to hell (or something along those lines) Izanami became the goddess of the underworld.