The Sword of the Imperial Regalia
When Susanoo hacked apart the eight-headed serpent, the edge of his ten-span sword chipped against something in the middle tail; splitting the flesh, he found a great blade within. Because clouds always massed above the serpent's lair, it was named Ame-no-Murakumo, Sword of the Gathering Clouds of Heaven. Susanoo presented it to Amaterasu, and at the heavenly descent it passed to Ninigi together with the mirror and the curved jewel, becoming one of the three imperial regalia.
Its later name comes from Yamato Takeru's eastern campaign. His aunt Yamatohime gave him the sword and a fire-striker bag at Ise. On a moor in Sagami (Suruga in the Nihon Shoki), a local chieftain fired the grass around him; the prince mowed down the grass with the blade and lit a counter-fire, and the sword became Kusanagi, the Grass-Mower. He left it with his betrothed Miyazu-hime in Owari before marching bare-handed against the god of Mount Ibuki, a lapse that cost him his life, and the shrine she raised to house it became Atsuta Jingu in Nagoya.
The Nihon Shoki records that in 668 the Silla monk Dogyo stole the sword but was turned back by storms. The Tale of the Heike tells how the regalia sword sank at Dan-no-ura in 1185 with the child emperor Antoku; by the account upheld at Atsuta, what was lost was a palace replica, while the original has never left the shrine, hidden as its sacred object. A replica still serves in the imperial accession rite today.
