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 attack on the Tanpopo base begins! The Yozakura family quickly discovers the enemy's top fighters--the Nijibana Rainbow Flowers--all have powers given to them by the Cherry Blossom Leaf Hazakura serum, and they are almost exactly like the Yozakura family's Bloomings! Shinzo clashes with Kurosawa, while Shion and Kengo tackle Chacha and Aonuma. Meanwhile, Kawashita spares no effort in setting up his mysterious Seed Sowing Project.