Original title (JP): 夏の庭 (Natsu no niwa, Summer Garden)

A delightful and moving coming-of-age story. One summer, three young boys take an increasing interest in an eccentric old man who lives alone in a house surrounded by an overgrown garden. The boys form a bond with the recluse and set about weeding and replanting the garden.

https://www.themoviedb.org/movie/115786