Fukamachi Yasunari♂

Fukamachi Yasunari is Ruu's uncle and a novelist. He is the brother of Ruu's mother, and takes care of Ruu while his parents are sorting out the issue of his custody. Yasunari welcomes Ikaru into his home, and also initially believes that Ikaru is a worried classmate of Ruu's. Yasunari used to date Akihito's sister, who died in an accident.

[from Wikipedia]