The sea serpent lived near Oki Island in a cave by the rocks and would frequently cause storms to rise. It required a maiden sacrifice every June 13th, and if it was not satisfied, it would call a storm that would sink the fleet of fishing boats.

A girl, Tokoyo, came forward to offer herself and she was sent to wait on the dragon. At the sight of him, she stood tall and when it tried to eat her, she pulled a knife and blinded its eyes. When it reared up in pain, she pushed the knife into its vulnerable throat and killed it.