Tunnel To Summer, the Exit of Goodbyes, The (Blu-ray) (Japanese Animation)

There is a phenomenon called the Urashima Tunnel, which exists outside the boundaries that constrain our reality. Unbound by such restrictions, it can achieve the otherwise impossible, journey wherever a mind can conceive, and bring the one thing that they most desire. But the cost of using the tunnel is staggering: a portion of one’s own existence. Yet… when Kaoru Tono discovers something matching the Tunnel’s description, he can’t help but think of the sister he lost five years ago. Can the tunnel really reunite them? And how is his school’s beautiful new transfer student involved?