Three murder cases take place in Tokyo. Numbers are left at the murder scenes, possibly hinting at where the next murder will take place. An investigation begins of the serial killer and Detective Kosuke Nitta (Takuya Kimura) works on the case. He believes the next murder will take place at Hotel Koruteshia Tokyo. To catch the killer, Kosuke Nitta goes undercover and begins working at the front desk of the hotel.