The Tunnel to Summer, the Exit of Goodbyes

One summer morning, high school student Kaoru Tono hears a city rumor about the mysterious “Urasima Tunnel”—an unusual passage that can grant any wish, but in return takes years of life. Kaoru doesn’t give it much thought, believing the legend is just a fabrication; however, that same night he accidentally discovers a tunnel that looks suspiciously like the one described.

Five years ago, his beloved younger sister Karen died.

Standing at the entrance, Kaoru understands: if the rumors are true and the tunnel really fulfills wishes, then maybe he has a chance to get Karen back.

After classes, he decides to investigate the find alone. But unnoticed by him, a newcomer follows as well—closed-off and enigmatic Anzu Hanasiro—who, for some reason, shows an interest in Kaoru.

Together, they choose to act in concert: to study the time-bending tunnel, uncover its secret, and move closer to their dream. But will they be able to accept the price they’ll have to pay for it?