Good Night Neighbor

Yeo-Eul despises thugs and womanizers, but her next-door neighbor, Un-Gyeol, seems to be both. Plagued by excess yin energy that attracts dangerous spirits, Un-Gyeol needs a woman's yang energy to save him. Realizing Yeo-Eul is the one who can solve his supernatural problem, he initiates a passionate physical relationship. While Yeo-Eul tries to keep their relationship casual, fearing he is a deceitful, rotten playboy, Un-Gyeol grows deeply, obsessively devoted. Is this fling bound for a friendly ending? Or will Un-Gyeol not allow it to end at all?

(Source: Tappytoon, edited)