Romance! A crazy, overprotective brother! And...spies?!

Taiyo Asano has been on his own ever since his parents died and the only one who seems to care for him is his childhood friend and classmate, Mutsumi Yozakura. But Mutsumi has a secret—she is the head of a family of spies! And on top of that, her brother Kyoichiro is dangerously protective of her! To stop Kyoichiro from killing him, Taiyo and Mutsumi must take the ultimate leap—marriage! Because in the Yozakura family, family cannot kill family.

The battle between Asa and the Yozakura family heats up! Kengo faces off against his old teacher Hulang. Does the secret to defeating her lie in the depths of her tragic past? Meanwhile, Kazu and Ryu challenge Shinzo. What is Ryu hoping to accomplish in siding with the enemy? It’s one all-out battle after another!