Now, open the door!

Moon Yeon-su, a returning college student who gets completely drunk, ends up accidentally entering the downstairs apartment on his way home- the password just happened to be the same. Inside, he witnesses a “union” (?) between his department’s TA, Yoon Do-a, and his classmate, Hong Yi-jae. After the shocking scene, the night passes, and the next day Yeon-su belatedly realizes the gravity of his own misdeed (?). “…What the hell, it’s that pervert from yesterday?” But unable to forget the pleasure of that night, Yeon-su crosses paths with the two of them once again, and thus begins Yeon-su’s chaotic and scandalous college life!