"Our Little Sister" is a simple, beautiful little film. It focuses on a small scale - a bunch of sisters who decide to start caring for their little half-sister after meeting her at their father's funeral - but the characters are universally relatable. It deals with themes of family, love, childhood, dealing with change, and human connection. If anything, this is a very human film.
The cinematography is gorgeous, but subtle and subdued. The film goes along with a slow pace, but this helps it focus on the great beauty of the small moments in everyday life. Although the slow pace of the film make take some time to get into, all the characters feel lovable but flawed by the end. All of the performances, including child actors, are spot on. The slow build up has major payoff because the sentimentality of the film doesn't feel forced or exaggerated. These emotional moments are played pretty straight, and they all work immensely well.
The film is simultaneously a coming of age story for the youngest sister, Suzu, and the oldest, Sachi, although it focuses on each character enough to feel emotionally attached to each one. Even most side characters are given a good degree of depth.
This is a beautiful family film that doesn't just focus on the effect of family, but finding your own family. It's about solidarity with the people one loves despite everything that each person has gone through (or is going through).