Ohikkoshi

Renko, a girl in the sixth grade, is at first unperturbed by her parents' decision to separate. With the companionship of her boyfriend, Minoru, and Sally, a classmate in the same boat, Renko gradually realises the practical implications of divorce, and tries repeatedly to get her parents to reconcile. An old man teaches her about the need to forget the past... - L.H. Wong, IMDb