Ken in human form.
Kiri's old dog named Ken, who she found on the street being bullied and tortured by boys. She saves him and takes him home, caring for him and feeding him. He was later returned to his owner but dies later because of a chronic heart disease. Ken comes back in human form in chapter 34, the third side story, watching and looking out for Kiri (even saving her from getting hurt when she fell down the stairs), as thanks for all that she did for him. In chapter 34, he did a lot for her. When she forgot her pencil case, he took Iori's pencil case. When she was hungry, he took all of Kei's snacks, and so on. When he was doing all that, everyone thought the culpirt was a ghostly creature/monster. Later on, Kiri knew it was all Ken's doing. He told her he asked God for a wish, a way to reply and say "Thank you" to the girl who saved him (meaning Kiri).
Ken, in human form, saving Kiri when she fell from the stairs.
Kiri cleaning Ken, in dog form, and taking care of him.