Night after night, Elva steps forth into the black sea with sword in hand, driving back creatures that surge forth from the waves - for he is one of the 'kannagi,' white-haired, ageless warrior priests chosen by the divine to protect the people of the island.

Although kannagi are destined to live short and lonely lives, Elva has found devoted companion in Alto, whose touch heals the black stains left by the cursed sea, and who has sworn to serve him and free him from his cursed fate.