Christmas Tree: February 1988 is the tenth chapter of Boku Dake ga Inai Machi manga.
Summary
The chapter starts with Akemi pushing her daughter's face in the sink full of cold water.
Satoru is seen with Yashiro in the staff room and Yashiro asks him if he knew why Kayo was absent or late on Mondays. He answers that she was hit on her face on Saturdays. As Yashiro expresses surprise, Satoru asks him why. Yashiro then explains that he couldn't reveal it to the class at the risk of her being bullied. He explains that he knew about the abuse but Kayo's mother hid it well. He tells him that Kayo's mother has been avoiding agents from Child Protective Services. He tells him that after the case is recognized, she will be put into protective custody and be taken away from the town.
While walking to class, he thinks about how Kayo had defended her mother before and decides to make up with Kayo. After class ends, Satoru runs after Kayo but loses her half way. The next day, he leaves his house early and thinks about how he must change the future. In school, he is completing his daily duty when Kayo comes to help. He greets her cheerfully as she sits down. Later, after collecting lunch money, Satoru realizes that it is gone. He then tells the teacher and Misato stands up to claim it was stolen by Hinazuki. She suggests searching everyone's backpacks and the money is found in Hinazuki' bag. Satoru then angrily snaps at Misato for accusing her. As Misato tears up, Yashiro calms everyone down by telling them that Hinazuki is on duty so it would be natural for her to have the money. Later, when Satoru and Kayo are taking the garbage out, she thanks him for what he did and tells him the reason why Misato hates her.
Satoru them remembers something and asks Kayo to accompany him to see a Christmas tree. He gives her his work gloves and they climb up the hill. He tells her about how he used to play there when he was little. As he mentions red foxes, two of them come running and run around their legs. They continue climbing after that and see the Christmas tree. She asks if he is stupid and informs him that it is February. He then suggests coming in the summer to look at the tree.