In a corner of the city center stands a five-year-old apartment building, located a seven-minute walk from the nearest station. This 12-story complex boasts 77 units, equipped with features like auto-lock doors and delivery boxes. One-room units are available for rent in the 70,000 yen range. Its proximity to convenience stores and supermarkets makes for convenient living, contributing to its popularity. A man working for the management company one day obtains the master key, kept under strict control. Flashlight in hand, a work-clad man quietly departs after placing a hidden camera deep inside a room. Darkness once again envelops the apartment, awaiting the next event.