The Tunnel to Summer, the Exit of Goodbyes: Ultramarine (Manga) Vol. 1

The award-winning, bittersweet sci-fi tale of a mysterious tunnel, time travel, and young summer love by the creators of Wait For Me Yesterday in Spring – inspired an anime film! And don’t miss the original light novel, also from Seven Seas.
Kaoru heard a rumor: The laws of space and time mean nothing to the Urashima Tunnel. If you find it, walk through and your heart’s desire will be on the other side…in exchange for years of your own life. The new transfer student Anzu promises to help Kaoru experiment with the mysterious tunnel—but what does she want from Kaoru in exchange? And what will he have left to give, after the tunnel’s done with him?