Now, Open Door!

While heavily intoxicated, returning student Moon Yeonsu mistakenly enters the apartment below his on his way home, as the door code is identical. Once inside, he inadvertently witnesses the "union" between his department's teaching assistant Yoon Doa and his classmate Hong Ijae. The shocking incident fades with the night, and the following day, Yeonsu realizes the seriousness of his actions. "What? It's that pervert from yesterday." However, unable to shake off the enjoyment of that night, Yeonsu finds himself encountering the two once more. Thus, Yeonsu's chaotic and scandalous college life commences.