19-year-old Natsumi Tsujimoto is late for her first day working at Bokuto Police Precinct located at Sumida. She ends up being pursued by Miyuki Kobayakawa, an 18-year-old female police officer who ultimately welcomes her to the precinct, after getting into several traffic altercations. A man in a red Mini, named OshÅ, is seen passing by the station, urging Natsumi and Miyuki to chase the car. They are contacted by him via two-way radio, informing them that he has installed fireworks that will go off in an unknown location in two hours. They figure out that the fireworks would be located under an airplane exhibited in a local park, only to find out that a boxed lunch was packaged there.