Kaoru Tono heard a rumor that the Urashima Tunnel was exempt from the laws governing time and space, and that those who discovered it could acquire their deepest desires, though it would come at the cost of their lifespan. As it turned out, Kaoru chanced upon a tunnel that bore a striking resemblance to the one in the rumor. Remembering his departed sister Karen, who died in an accident five years ago, Kaoru's mind wandered. To his surprise, Anzu Hanaki, a new student, followed him and offered to join him in investigating the mysterious tunnel. However, what would Anzu demand from Kaoru in exchange, and what would be left for him once the tunnel had exacted its price?
