Susano-o-no-mikoto(hero), Yamata-no-Orochi(giant serpent), Inada-hime(the eighth daughter), Tena-zuchi and Ashina-zuchi(elderly couple)
The Goddess of the sun, Amaterasu Omikami, hid herself in Ama-no-iwato, the gate of the Celestial Cave, as she was angry with the evil deed carried out by the younger brother Susano-o-no-mikoto.
Ousted from Takama-ga-hara, Heaven and the home of all deities, Susano-o-no-mikoto wandered around the continent and stopped at the Hikawa-river at Izumo, Japan, and met a mournful old couple and Princess Inada.
He asked why they were sad, and the old couple answered that Yamata-no-orochi, the Eight-forked Serpent, appears every year and that they have to sacrifice one daughter every year.
Sven daughters had already been eaten by the Serpent. Their last daughter was soon to be offered as sacrifice to Orochi.
Susano-o-no came up with a plan, which was to put a barrel of poisonous sake made of various nuts to Orochi.
The giant serpent then appeared, drank the sake and fell asleep. Susano-o-no cut Orochi to pieces and killed it.
A sword emerged from the tail of Orochi, which he named Ameno-murakumon-no-tsurugi. He dedicated the sword to Ameterasu and married Princess Inaba.