Tsubaki is a third year student and also the younger less known sister of Suoh Mikoto: The Red King. She hasn't been able to see him in four years, but she yearns for his embrace and presence. But at the end of the day, her brother doesn't pay her any attention ; so Tsubaki goes elsewhere. Meeting a young man by the name of Fushimi Saruhiko -a former HOMRA member. She ends up falling in love with him, and decides to join his group known Scepter 4. Siblings will collide and with every fight, hearts break and power awakens. How will Tsubaki learn to control her emotions when she sees the person the loves the most fight against her?