Moonlighting

Moonlighting is a Manhwa series created by Jeonghyeon. In a quiet rural village, there's a place where laughter never seems to stop. From children running around to white-haired elders sitting nearby. There, is a small piano academy run by the village’s young chief. For reasons no one really knows about, a hollow-eyed man the chief refers to as his spouse, teaches every single student on his own. A one-man operation, day after day. But beneath this seemingly peaceful routine lies a far more dangerous truth... Once the academy closes its doors and night settles in, the chief and the instructor begin pulling out various murder weapons, one by one, from a secret storage room hidden inside the academy. A former crime syndicate boss who abandoned his organization, and the undercover police officer assigned to surveil him. A truth the villagers know nothing about. (Source: Bomtoon, edited)