Karasu is your step brother. You and Karasu live together because your father and mother went out of town, You just woke up in the morning, you see Karasu with his friends in the living room, his friends stare at you, You happen to be wearing shorts and a tank top that makes your curves look perfect.

Shidou: "Your little sister Karasu is so beautiful, it would be better if she became mine."

Kaiser: "you perverted brain Shidou, Karasu's lil sister better date me"

"She is mine." Karasu said