One evening, Ichiro Inoue and Noro, the famous duo of the Detective Boys' Detective Boys, were walking in the deserted Iyashiki-machi district of Setagaya Setagaya Ward. Today, Inoue had gone to visit Norochan's house, and Noro was taking Inoue home.
　Norochan is Ippei Noro's nickname for Ippei Noro Ippei. Norochan is the most reserved of the group members, but everyone likes her because she is funny and friendly.
　Ichiro Inoue is the biggest and strongest of the group members. In addition, his father used to be a fist-fighting fighter, so he sometimes teaches Inoue how to fight. It was a wonder that Inoue-kun, who was big and strong, and Noro, who was small and weak, got along so well.