The Tsutsuga Mirrors were originally a treasure of Futarasan Shrine, formed of a male and female pair. The female mirror has the power to entrap souls, and is called the soul-sealing mirror (Fuukonkyou—封魂鏡), while the male is able to release entrapped souls. Legend has it that when Holy Priest Shoudou founded the first shrine on the Nikkou mountains, he turned the two tsutsuga causing mischief on Nantai-san into magic mirrors with his spells.

Four hundred years ago, the Fuuma Clan mated the two halves of the mirror to give birth to a tsutsuga cub which High Priest Tenkai sealed into the female mirror by order of Tokugawa Ieyasu.