Mi-hun leads a solitary life, restrained within the four walls of his home following the demise of his parents. However, his mundane existence takes an unexpected turn when he comes across the enigmatic raincoat-clad neighbour who recently shifted in next door. Bizarre occurrences begin to unfold, and Mi-hun discovers a strange correlation between the inexplicable instances of 'spontaneous human combustion' in his town and the raincoat man. Inquisitive and unable to resist his curiosity, Mi-hun begins to monitor his new neighbours, unknowingly proving to be his most significant error yet.