Taiyo Asano is a very timid secondary school understudy and the main individual he can converse with is his beloved companion, Mutsumi Yozakura. For reasons unknown, Mutsumi is the little girl of a definitive covert agent family! Surprisingly more dreadful, Mutsumi is being irritated by her overprotective, bad dream of a sibling, Kyoichiro. What intense advances will Taiyo need to take to spare Mutsumi?! A covert agent family satire - the mission starts!