Hiroshi arrives at his new apartment eager to settle in after an affordable move, brushing aside local tales of hauntings. As he and Kotobuki prepare for a small housewarming gathering, scattered machine parts on the floor trigger an unexpected short-circuit and blast. The explosion opens a gap in the flooring that uncovers a mysterious jar, releasing a blonde snow fairy who introduces herself as Ruri and sets an unforeseen cohabitation in motion.