Jachwibanggaeron

Se-Cheong, a returning student living alone and a homebody, is plagued by noise pollution from his upstairs neighbor. She tried leaving notes and even visiting, but to no avail. Furious at the handsome, unassuming upstairs neighbor, Se-Cheong embarks on a series of cute(?) revenge plots, never knowing how they'll resonate.

"Hey, you're the same age as me."

There's no such thing as too much bad blood, and to think they'll end up running into each other during a group project! The upstairs nuisance is Seo Kang-Hyun, a famous, popular, and gossipy Western painting major. He's someone from another world with whom he'd never normally associate, but what's his ulterior motive? Kang-Hyun slowly begins to penetrate Se-Cheong's wary heart... What will happen if we, who are polar opposites in every way, meet? A full-fledged single-person romance, Introduction to Living Alone.

(Source: KakaoPage, translated)