Niiyama Shinobu

Shinobu is the protagonist of this story. He has a stepsister, Aoi, who is an idol. His childhood friend Eriko is living in the same neighborhood with him and works as a teacher in his school, she is also his homeroom teacher. She cooks for him meals at home every day. Shinobu's parents are not at home often due to their work. Most of time he stays alone when Aoi is away for her job.