In 2157, the Gingarou Hotel, a luxury property in Ginza, Tokyo, utilizes advanced hotelier robots to deliver top-tier hospitality. Regrettably, the hotel has seen no guests for decades, since humanity abandoned Earth long ago due to its toxic atmosphere. Yachiyo, the robot serving as "acting acting manager," works diligently each day with her mechanical staff to maintain the hotel in pristine condition. Over the years, numerous employees have stopped functioning, with no prospect of repair or replacement. Nevertheless, Yachiyo persists in her duties, honoring the promise she made to the hotel's owner before he left. She holds onto the optimism that humanity will eventually return to Earth—and that she will reunite with the owner.