The Tunnel to Summer, the Exit of Goodbyes

Kaoru Touno’s home life has unraveled: after losing a sibling and watching his parents’ marriage end, peace feels out of reach. A fierce argument with his father sends him fleeing into the night, where he stumbles upon a strange tunnel that seems to draw him inside. Shaken by what he witnesses, he bolts for the exit—only to emerge holding a bird that looks exactly like the pet he once lost.

What feels like mere minutes in the tunnel turns out to be a full week in the outside world. Kaoru recalls whispers of the “Urashima Tunnel,” said to grant a person’s deepest wish at the cost of their lifespan, and the impossible return of his bird makes him wonder what else it could change. When he goes back, he finds he isn’t alone: Anzu Hanashiro, a newly transferred classmate who knows the same rumor, has followed him and proposes they test the tunnel together—because she, too, has something only it can give.