In the dark waters of Japan's Sagami Bay, legend has it that three decapitated samurai heads sometimes appear, dancing in the moonlight. These vengeful spirits, called Maikubi (舞首), are said to be the tormented souls of three warriors - Kosanta, Matashige and Akugorō - who, during a festival in the XIIIᵉ century, drunkenly killed each other in a brawl.

Their heads, which fell into the sea, never found rest. Since then, they emerge at night, spitting flames and creating tomoe-shaped waves (巴), the spiral symbol of feudal Japan. Fishermen avoid these cursed waters, fearing shipwrecks and curses.

This legend, recorded in the Edo period illustrated work Ehon Hyaku Monogatari, illustrates the fine line between the world of the living and that of spirits in Japanese folklore.