A sword which is currently in the Japanese royal Regalia, supposedly from mythical times. It is often depicted as a katana in fiction, however the most reliable images show it as a older form of short sword.
In The King of Fighters series, the main character Kusanagi Kyo holds the weapon inside his body, so as to make him be able to wield flames and seal Orochi.
In the Len'en series, Adagumo no Yaorochi was born from Orochi's severed arm and because of this, he/she has a connection with the sword, whose real name is Tasouken (蛇叢剣).
