Kusanagi-no-Tsurugi

Cast out of heaven, the storm god Susanoo came to the land of Izumo and met Yamata-no-Orochi, a great serpent with eight heads and eight tails that devoured a daughter every year. He set out eight vats of strong liquor, got the serpent drunk and hacked it to pieces. When he cut the middle tail his blade struck something and chipped, and inside he found a sword.

Susanoo named it Ame-no-Murakumo-no-Tsurugi, the sword of the gathering clouds of heaven, and presented it to his sister, the sun goddess Amaterasu.

Later, when the hero Yamato Takeru campaigned in the east, enemies set fire to the fields around him. He drew the sword, cut away the grass around him and lit a counter-fire, and the flames turned on his enemies. From then on it was called Kusanagi, the grass-cutting sword. It is said to be enshrined at Atsuta Shrine in Nagoya, but it has never been shown to the public.

The photograph shows straight swords from Japan's Kofun period in the sixth century. Before the Kojiki was written, the swords carried by heroes of myth were straight like these rather than curved.