When Yonaga Hokuto turned 5 years old, she was taken by her father to visit the mansion of the Fudo Zaibatsu. Standing there are beautiful identical twins, Tsuzuri and Katari, who are the heirs of the Fudo family. Thirteen years after being sold by her father as their "play partner" for the capricious and sadistic twins, who are the exact opposite of their beautiful appearance, Yonaga has been suppressing her loneliness while telling herself that it is for the happiness of her parents. , being at the mercy of their "games". While secretly harboring hatred for the twins who derailed her life. However, when they entered university and started living together, the relationship between Tsuzuri and Katari over Yonaga gradually began to crack. One day, a man named Yagami appears before Yonaga... A forbidden love-hate story full of beautiful madness begins here.