Chihiro lives with her only son Kenta in an old house since her parents' generation. The 80-year-old house is quite rattling, and Chihiro decides to take the plunge and renovate the house... Chihiro receives a suggestion from the renovation company that he received a quote and entrusts the design to someone called Takumi, and that if he receives a little interview, the cost will be significantly reduced. Chihiro replies and takes the suggestion, but he never imagines that his decision would cause a serious incident in the future...