Four childhood friends who have been together since forever, even attending the same high school. Going to school together, spending breaks together, eating lunch together, and heading home together. They’ve spent every moment together... and thought they'd be 'Best Friends Forever.' One day, Meisa, the cheerful mood-maker of the group, was seen kissing a teacher... Itsuki and Karin witnessed it and were deeply shocked. Later, when they confronted her about it... Itsuki mumbled, 'Actually, I like him too...' then the others chimed in, 'Me too,' 'Wait, I do too!' It turns out all four of them are in love with the same teacher. A middle-aged teacher... it doesn't matter. Breaking school rules, or even the law... it doesn't matter. Public reputation is out of the question. A teenager's love has no room for calmness; it is purely fueled by passion. When a frantic Yuina tries to keep him all to herself, Itsuki and Karin decide they can't let it slide, leading to a three-way harem struggle for the teacher while Meisa watches from a distance... Later, they gather the teacher for their first-ever 'confrontation.' To have the teacher decide who is number one, a 'no-holds-barred' battle of sexual conquest begins. Who will be the one he chooses in the end...?