Rin Okumura is the daughter of Satan which she found out before she went to Blue Cross Acadmany, but after the camping trip and everyone found out she was Satan daughter they began calling her names treating her badly. Even her own older twin brother treats her badly. She began beliving everything they said, that she was a monster, a demon. Her last strike is when her own twin brother tried to..... anyway after such event she ment to Mephisto who was angered by what has happended to his little sister. Which many dont know that demons are extremly overprotetive over their younger siblings. He offered her to go to a place that she will be loed by her ture family.