Hirokazu Kore-eda’s luminous adaptation of Akima Yoshida’s manga series Umimachi Diary is a stealth masterpiece. Like his other films, Our Little Sister never draws attention to itself (or to its maker’s understated brilliance). He simply depicts four sisters going about their lives in coastal Kamakura, where plums grow freely, mackerel is plentiful, and the air glistens with humidity. The women have their flaws, like a fondness for the wrong men, but the better you get to know them, the harder it is to let them go. In that sense, his 12th narrative feature plays more like a miniseries than a movie.

Sachi, Yoshino, and Chika (Haruka Ayase, Masami Nagasawa, and Kaho), who range in age from 19 to 29, meet their 14-year-old half-sister, Suzu (Suzu Hirose), for the first time at their estranged father’s funeral. When they notice her stepmother’s casual disregard, they offer to take her in (Suzu’s late mother was their father’s mistress). It’s the best thing for all concerned, since their grandparents are gone and their mother would rather spend time with her second husband.

What follows contradicts the conventional Hollywood approach to domestic drama. There’s no period of adjustment, no major conflicts, and no external forces threatening to tear them apart. The soccer-playing Suzu simply lights up the Agano household with her energy and enthusiasm. Although Kore-eda never spells it out in so many words, her newfound family has saved the girl from a life that threatened to dim her spirit.