川上 悠馬

Spoiled younger brother.
After the hospitalization of his mother, he thought about living on his  own, but still relies on his sister. 
His body still looks innocent, but he is slowly becoming more manly.
Because his face is like of a girls, he is secretly popular in class, yet girls in the same grade treat him like a child.
He has no sexual experience, never masturbated before either.