Constable Shouji Maezono of the Kumamoto Prefectural Police assists Tokyo visitor Natsuna Keyaki in searching for her missing friend, Itsuki Kusunoki. He accompanies her to the town hall for inquiries, though privacy regulations prevent officials from sharing details. During their walk back, they encounter local junior high student Izumi Chiba, an acquaintance of Shouji. Izumi privately confides her unexpressed romantic feelings for him to Natsuna. Later, when Izumi emotionally hugs Natsuna, her father Shigezo Chiba misinterprets the interaction, partly aware of Izumi’s affection for Shouji. Throughout Natsuna’s search, Shouji provides transportation in his personal DMC DeLorean. He sees her off at Kumamoto Airport when she prepares to depart, but after she abruptly leaves check-in upon locating a lead on Itsuki, he drives her toward Sakitsu. During this journey, his DeLorean suffers mechanical failure on the highway, compelling Natsuna to complete the final stretch on foot.