Heavily drunk, returning student Moon Yeonsu accidentally enters the apartment downstairs—
the door code just happening to be the same.

Inside, he witnesses a certain union (?) between Yeondu, a departmental teaching assistant,
and Hong Lee jae, a fellow student.

The night passes after the shocking scene.

The next day, Yeonsu finally comes to realize the gravity of his own misconduct (?).

“...What the hell? You’re that pervert from yesterday, aren’t you?”

But unable to forget the pleasure of that night,
Yeonsu once again finds himself crossing paths with the two of them—

And thus begins Yeonsu’s chaotic, scandalous college life!