Battle Heater(1989)

Original title: バトルヒーター

Furuchi and Hama are a pair of unsuccessful repairmen and electronic engineers. Out in the fog late one night, Furichi finds a so-called Kotatsu space heater. Bringing their haul home to their apartment building chockfull of eccentrics leads to punk rock delinquency, murder, suicide by clock, and one cursed Kotatsu driving their electric bill into overdrive, not to mention craving human flesh.