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 Yozakura siblings take a trip to the ominous and decaying Yozakura Mansion, which is said to be haunted! There they are confronted by the second head of the Yozakura family, Lady Ninomae. But she's supposed to be long dead, so what does it mean?!.