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. Kyoichiro activates his True Spring Blossoming, putting his life on the line in hopes of pulling Taiyo away from Asa's control. Meanwhile, the twins run into the first Yozakura, Tsubomi. She asks them to help her feed Momo power so he can break free of Asa's control. Many questions remain in the final fight! Will Taiyo wake up? Can Asa truly be defeated? The Yozakura family's biggest mission reaches its thrilling conclusion!