Kusukuni Takashi, a student short for his age with a youthful face, has always been treated like a little brother by his cousin Takasu Yoshika, his dentist Amamiya Imari, and the massage parlor employee Nagaoka Rito. They constantly pamper and tease him. However, it comes to light that Imari and Rito have been scheming to monopolize Takashi and take his chastity. Yoshika, determined to protect her cousin, and Imari and Rito, driven by their desire to make Takashi their own, begin making bold advances toward him every day. As each girl starts pulling out all the stops to win Takashi's affection, a battle for his heart begins.