One day Susano-o, the God of Storms, frightened his sister Amaterasu, the Sun Godess. She ran into a cave and closed the entrance. The other gods began a party with birds singing and displayed beautiful jewellery and a mirror outside the cave. Amaterasu heard the laughter and became curious. She opened the entrance and the other gods drew her out.

Susano-o was banished to the land of Yomi. There he fought against a giant eight-headed serpent. When he cut off one of its eight tails, he found a magnificent sword. Later he gave the sword to his sister Amaterasu, because he felt he was unworthy of it. The sword was known as Ama-no-Murakumo-no-tsurugi (Sword of Gathering Clouds of Heavens).

Later Amaterasu sent her grandson Nigi-no-Mikoto to pacify the Japanese Islands. She gave him the Sacred Mirror, the Sword of Gathering Clouds of Heavens, and Jewels. They became the Japanese Imperial Regalia, but they were lost in the 12th Century.