One summer morning before school, Kaoru hears an unsettling rumour – of a mysterious tunnel that can grant any wish to those who enter it, but ages them dramatically in exchange. At first, he writes it off as nothing more than an urban legend, but that very night, he happens upon the same passage: the Urashima Tunnel. As he stands before its gaping maw, a thought occurs to him: if this tunnel truly does have the power to grant any wish, could he use it to bring his younger sister back from her untimely death five years prior?

One summer morning before school, Kaoru hears an unsettling rumour – of a mysterious tunnel that can grant any wish to those who enter it, but ages them dramatically in exchange. At first, he writes it off as nothing more than an urban legend, but that very night, he happens upon the same passage: the Urashima Tunnel. As he stands before its gaping maw, a thought occurs to him: if this tunnel truly does have the power to grant any wish, could he use it to bring his younger sister back from her untimely death five years prior?

[Source: Anime Limited]