Fujisaki Nagihiko is the eldest son of the Japanese aristocratic Fujisaki family. In order to save the corrupt family, he can only approach the Vongola X generation. Unknowingly, Fujisaki Nagihiko is moved by the kind and innocent Sawada Tsunayoshi. But at this time, the family has a new order to marry the eldest daughter of the Sanzenin family, Sanzenin Ruasa, a time-travelling girl who has been pampered since childhood. What would he do?