Yuhi and Yasumi, who are both voice actresses that attend the same high school. They host a radio program together. They are diametrically opposed in appearance and personality, and they get into fights when they are not on air.

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.