Muakumogiri and Yoru 3D print model

The history of the Kusanagi-no-Tsurugi extends into legend. According to Kojiki, the god Susanoo encountered a grieving family of kunitsukami (gods of the land) headed by Ashinazuchi (足名椎) in Izumo Province. When Susanoo inquired of Ashinazuchi, he told him that his family was being terrorized by the fearsome Yamata no Orochi, an eight-headed serpent of Koshi, who had consumed seven of the family's eight daughters and that the creature was coming for his final daughter, Kushinada-hime (奇稲田姫). Susanoo investigated the creature, and after an abortive encounter he returned with a plan to defeat it. In return, he asked for Kushinada-hime's hand in marriage, which was agreed. Transforming her temporarily into a comb (one interpreter reads this section as using a comb he turns into [masquerades as] Kushinada-hime) to have her company during battle, he detailed his plan into steps.

He instructed that eight vats of sake (rice wine) be prepared and put on individual platforms positioned behind a fence with eight gates. The monster took the bait and put one of its heads through each gate. With this distraction, Susanoo attacked and slew the beast (with his sword Worochi no Ara-masa), chopping off each head and then proceeded to do the same to the tails. In the fourth tail, he discovered a great sword inside the body of the serpent which he called Ame-no-Murakumo-no-Tsurugi. He presented the sword to the goddess Amaterasu to settle an old grievance.

Atsuta Shrine in Nagoya dates back to 100 CE during the reign of Emperor Keikō and houses the Kusanagi sword. Generations later, during the reign of the 12th Emperor Keikō, Ame-no-Murakumo-no-Tsurugi was given to the great warrior, Yamato Takeru, as part of a pair of gifts given by his aunt, Yamatohime-no-mikoto, the Shrine Maiden of Ise Shrine, to protect her nephew in times of peril.

These gifts came in handy when Yamato Takeru was lured onto an open grassland during a hunting expedition by a treacherous warlord. The lord had fiery arrows loosed to ignite the grass and trap Yamato Takeru in the field so that he would burn to death. He also killed the warrior's horse to prevent his escape. Desperately, Yamato Takeru used the Ame-no-Murakumo-no-Tsurugi to cut back the grass and remove fuel from the fire, but in doing so, he discovered that the sword enabled him to control the wind and cause it to move in the direction of his swing. Taking advantage of this magic, Yamato Takeru used his other gift, fire strikers, to enlarge the fire in the direction of the lord and his men, and he used the winds controlled by the sword to sweep the blaze toward them. In triumph, Yamato Takeru renamed the sword Kusanagi-no-Tsurugi (Grass-Cutting Sword) to commemorate his narrow escape and victory. Eventually, Yamato Takeru married and later fell in battle against a monster, after ignoring his wife's advice to take the sword with him.