The Urashima Tunnel grants a wish to those who enter... with a price.

Kaoru Tono appears elusive but has a heavy heart rooted in a traumatic accident in the past. Anzu Hanashiro seems stronghearted but suffers from the gap between her ideal self and reality. The two team up as allies to investigate the mysterious tunnel in order to get what they want. It is an unforgettable, nostalgic story that sweeps past a summer in the countryside.