The gods Izanagi and Izanami gave birth to the islands of Japan, and to the rivers, the mountains, and the trees. They gave birth to the Sun Goddess, Amaterasu, and to the Moon God, Tsukiyomi. But it is with their third child, Susano-o the Storm God, that this adventure truly begins, for it was Susano-o who slayed the eight-headed serpent, and in that serpent's tail that Susano-o discovered the great sword known as Grasscutter.