Horigai Sayo is 22-years-old and she will soon graduate from a university. She has already been working in a child welfare job. She is 170 cm. tall and people think she is a bit eccentric, but she doesn't care what others think about her. She spends her time working part-time, attending classes, and going back to a boarding home. She meets Inogi Kusuko, who attends the same university. Kusuko has lived through a painful experience in her past. One day, Sayo's friend Suiho Nao kills himself.
