A Useful Ghost

March is mourning his wife Nat who has recently passed away due to dust pollution. He discovers her spirit has returned by possessing the vacuum cleaner. Being disturbed by a ghost that appeared after a worker's death shut down their factory, his family reject the unconventional human-ghost relationship. Trying to convince them of their love, Nat offers to cleanse the factory. To become a useful ghost, she must first get rid of the useless ones.