A Dark Rabbit Has Seven Lives

いつか天魔の黒ウサギ

As a child, Taito Kurogane met the vampire girl Saitohimea, who placed on him a pact that lets him revive after death up to seven times before she pays the price. Years later, an injury has convinced him he is an ordinary high schooler, until Himea returns and his sealed memories begin to surface. The bond between them drags him toward forces from a parallel world that once imprisoned her.