A dilapidated mansion sits on the outskirts of Seoul. Among its residents are frauds, murderers, and psychopaths, all seeking refuge in the only place that will accept them. But not every resident of the run-down manor has come here by choice. Kim Sungkyung operates a minimart so that he can afford to take care of his parents, who have come down with a malignant disease. Having been born inside the four walls of the mansion, a life of depravity and deprivation is all he knows. The sole thing that gets him through is his obsession with the building’s manager, Kwon Cheong-rim: a cruel and calculating figure seemingly only interested in the preservation of his own wealth and power. So when the enigmatic pretty boy begins to hint at a sort of faint interest in Sungkyung, the latter's obsession begins to grow as a single question echoes ceaselessly throughout his mind: “Why...?”