It's 2022 in Tokyo, and it's become commonplace for numerous drones to fly through the sky. One day, Yazaki Yui (Mori), a chief appraiser working at a real estate company, and his subordinate Kobayashi visit a condominium they have purchased to view it. Just as they are about to return to the office after taking care of their business, the two are enveloped in a pure white light. A "drone believed to be carrying a biological weapon has crashed," and they are forced to take refuge in a shelter on the third basement floor until decontamination is complete. A time and space just for the two of them. And then...