Chapter 3 contains diary entries written by Naoki’s mother, Mrs. Shitamura, framed by narration from one of his older sisters, Kiyomi, who finds her diary after explaining that Mrs. Shitamura was found with a stab wound to her stomach.

Mrs. Shitamura hates Moriguchi. Married with two daughters and a son, Mrs. Shitamura is contemptuous of Moriguchi’s status as a single parent and believes that Manami shouldn’t be allowed in Moriguchi’s workplace. She does not think that Moriguchi is an appropriate teacher for Naoki and writes to the school requesting that someone like Werther be Moriguchi’s replacement. She and Naoki had witnessed Manami’s tantrum in the store about the Snuggly Bunny pouch; Mrs. Shitamura believes Moriguchi should have bought the pouch. When Moriguchi comes to their house to investigate Manami’s death, Mrs. Shitamura is furious at her implication that Naoki is a perpetrator; she offers Moriguchi money as compensation for her dead daughter, but Moriguchi refuses.

Since the last day of school, Mrs. Shitamura has noticed Naoki’s depression and increasingly strange behavior. He refuses to eat communal food and begins washing his own dishes and clothes. Conversely, he refuses to bathe and no longer likes physical touch.