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 race to track down Tanpopo member Kawashita is on! Taiyo goes undercover at a high-class hotel that sources say has ties to the evil organization. He makes his way to the top floor only to find a new enemy awaiting him! How can Taiyo hope to beat a monstrous foe pumped full of the new secret drug known as Cherry Blossom Leaf Hazakura, which was manufactured to replicate the Yozakura family's blood?!