Slaying the Yamata-no-orochi
Susanō-no-mikoto, expelled from Takamagahara, descended to Torikami in the upper stream of the river of Hikawa in Izumo. There, he found a chopstick drifting down the river, thought there are people upstream and went to see.
Then he found an elderly couple, crying with a beautiful girl in between and asked why they are crying. The old man is named Ashinazuchi, and the old woman is Tenazuchi, and their daughter is Kushinadahime. The two had 8 daughters, but the Yamata-no-orochi came from Koshi to eat their daughters every year, and it will be coming soon to eat their last daughter Kushinadahime. Susanō-no-mikoto asked how the Yamata-no-orochi looks like, and Ashinazuchi said, that it's eyes are red as Akakagachi, it has 8 heads and 8 tails, Hikagekazura, Hi and Sugi are growing from it's body, it has the length to lie across 8 valleys and 8 mountains and it's belly is always bloody.
Susanō-no-mikoto, who became to love Kushinadahime, offered to take down the Yamata-no-orochi, on condition that he can marry her. The couple, who came to know that Susanō-no-mikoto is Amaterasu-ōmikami's brother, accepted this offer.
Susanō-no-mikoto changed Kushinadahime into a comb with his jintsūriki, and wore it in his hair. And also, he told Ashinazuchi and Tenazuchi to make a hard liquor brewed many times, to put a fence around with 8 gates, and place a barrel filled with the liquor in each of them.
Waiting prepared, the Yamata-no-orochi came and it dunked each of it's heads into the barrels to drink. As the Yamata-no-orochi got drunk and started to sleep, Susanō-no-mikoto chopped up the Yamata-no-orochi with his Totsuka-no-tsurugi. When he cut the Yamata-no-orochi's tail, his sword got chipped. He wondered why and saw what is insideto find a sword in the tail.
Susanō-no-mikoto presented the sword to Amaterasu-ōmikami in Takamagahara. This sword is the Kusanagi-no-tachi.