Four-year-old Kun is an only child — this is, until his parents bring home a baby sister named Mirai (the Japanese word for future) and the boy gets rattled by the new addition to the household. Not much there for a full-length feature film … or so you’d think. Except you are in the presence of Japanese animation artist Mamoru Hosoda (Wolf Children, Summer Wars), who again transforms the seemingly conventional into a magic carpet ride of time and memory. It makes all the difference.

Released in an English-dubbed version, Mirai...