Kokubunji, a Uni student with a rugged face, endures harsh training everyday in order to protect his friend, Ishibashi, who has an angelic smile and a supple body.── During class, club activities, and on holidays, he must carefully observe Ishibashi, so that he does not face danger! For his beloved Ishibashi, Kokubunji must struggle on a daily basis! He is tested to act logically, constantly! He is in defensive war for his best friend, with the Uni's top student (with a dirty mind). 強面の某大生・国分寺は、厳しい訓練に耐えている。すべては友人の石橋を守るためだ。天使の笑顔にしなやかな身体──授業中や部活中はもちろん、休日も彼に危険が及ばぬよう、常に注視していなくては！愛しの石橋のため、国分寺は本日も奮闘す！！常に理性が試される──！首席某大生（むっつり）による、親友防衛戦。