Karin, a high school girl, is sent to live with her relatives while her father is undergoing divorce mediation due to domestic violence. There, she finds three beast-like brothers living. Every day, she endures the abuse of her silent eldest brother, the violent second brother, and the perverted third brother, who don't choose where they are, with a clouded expression on her face. Then the day arrives when all the relatives are to gather. She herself has no idea about the greatest tragedy that will occur in the future...