These are the twilight years of the danchi, the public housing units built during Japan’s postwar economic boom. Once a common sight, the utilitarian concrete apartments are now rapidly dwindling in number — taking with them the dreams of a simpler, more optimistic age.

In “Drifting Home,” director Hiroyasu Ishida suggests that it isn’t just old fogeys with long memories who feel a pang of emotion when such relics disappear. The story’s protagonists are still in elementary school, but when a local danchi gets earmarked for demolition, it’s clear that some of them aren’t yet ready to say goodbye.

The housing complex in question is where sixth graders Kosuke (voiced by Mutsumi Tamura) and Natsume (Asami Seto) spent the early years of their childhood, under the watchful eye of the latter’s grandfather, Yasuji. Things haven’t been the same between them since Yasuji died, but Natsume still clings to the memory of the old man’s apartment as a haven where she could escape from her parents’ imploding marriage.