Kusanagi no tsurugi

• Japanese: 草薙剣 (kusanagi no tsurugi)

Kusanagi no tsurugi, or the "Grasscutter Sword," is one of the three Japanese Imperial Regalia, along with the mirror Yata no kagami and the jewel Yasakani no magatama.

The sword is said to have been held by the Imperial family ever since, according to the earliest Japanese creation myths, the storm god Susa no O no Mikoto, brother of the sun goddess Amaterasu, slayed the demon serpent Orochi and discovered the sword within the serpent's body.

The original Kusanagi sword is said to have been housed permanently at Atsuta Shrine since the reign of the legendary Emperor Keikô (r. 71-130). However, from the Meiji period onwards, a replica has always been kept close to the Emperor, and in the Meiji period up through 1945, the emperor carried this replica on his person whenever he left the Imperial Palace for an overnight (or longer) trip.

The sword is said to have been lost or stolen on a number of occasions, most famously in the 1185 Battle of Dan-no-ura, when it supposedly was lost into the sea along with the young Emperor Antoku and many prominent members of the Taira clan. While some accounts assert that it was only a replica that was lost, others say that that was the true sword, and that the Kusanagi housed at Atsuta since then is a replica made in 1210. The sword is also said to have been stolen by a Korean monk in 668 and returned in 686.