Two classmates navigate their relationship – along with a magical tunnel where time gets dilated – in Tomohisa Taguchi’s elegant animation

The Planet of the Apes and the waterworld in Interstellar aren’t the only places in cinema where the time dilation phenomenon can be observed. A few metres down the railway track from a smalltown station in Tomohisa Taguchi’s anime romance, downtrodden hero Kaoru (Oji Suzuka) slips down a bank to find a cleft in a rockface; it gives on to the Urashima tunnel, a magical passageway capable of granting your greatest wish. But mere seconds spent in this molten-canopied alley chasing after your heart’s desire equate to hours on the outside; minutes mean years.

Kaoru wants to bring his younger sister, Karen, back to life; his alcoholic father blames him for her death. And he finds an unexpected ally in Anzu (Marie Iitoyo), the new girl in his high-school class to whom he lends an umbrella one morning at the station. As they investigate the tunnel, and try to pin down its properties, Kaoru is drawn increasingly closer to this soft-spoken but hard-nosed free spirit – and troubled by her egotism in wanting to forge on inside to acquire the talent to become a superlative manga artist.