Set five years after "Saito San," Masako Saitou (Arisa Mizuki) now has a son in the 4th grade of elementary school. She moves to a new town and meets new people. Masako Saitou faces many problems at the elementary school and has to deal with the parents of her son's classmates and also the teachers.

The righteous Saito Masako (Mizuki Arisa) boldly confronted those who ignored the rules of society regardless of who they were when her son Junichi was in kindergarten. Now Junichi is a fourth-grade elementary school student and the Saitos live in a new neighbourhood.