The mood of “In This Corner of the World” shifts, underscored by the percussion of distant bombs. (Shout! Factory/Funimation Films)

Set against the backdrop of pre-atom-bomb Hiroshima, the Japanese animated film “In This Corner of the World” proceeds under the dreadful weight of what is to come, as the calm of everyday life — carried out by ordinary civilians and rendered in bright colors — eventually gives way to air raid sirens. Directed by Sunao Katabuchi, the film is deceptive, keeping its exact message obscure until its final minutes.

As it opens, Suzu is a young woman living in Hiroshima with her family. Time passes quickly — skipping a decade in what feels like minutes — until Shusaku, a young man, offers Suzu a marriage proposal. She accepts, moving with him to the nearby seaside town of Kure. With her warm disposition, Suzu develops a rapport with her niece, Harumi. Although everyone is aware of the escalating war, they rarely talk about it, until it can’t be avoided.

The film’s tension, in part, arises from the question of whether its characters are innocent or willfully ignorant. At times, Suzu seems overly naive, as when she and Harumi casually catalogue warships in the harbor. Slowly, the mood of the film shifts, underscored by the percussion of distant bombs.

Katabuchi does not shy away from horrific war imagery, ending the film with a heartbreaking coda. But by focusing on Suzu’s ordinary life before the war, he gives her fate a universal resonance.

Based on manga by the Hiroshima-based artist Fumiyo Kouno, “Corner” adopts Kouno’s pastel palette and exaggerated facial expressions. Yet it hews to realism — at least until the spreading horror is so extreme that hallucinatory imagery is the only way to make sense of it. “Corner” is a deeply sympathetic tale, using the possibilities of animation not just to pique curiosity, but to devastate.

PG-13. At area theaters. Contains violence and war imagery. The film will be shown in two versions: Japanese with subtitles and dubbed in English. 128 minutes.