Tsuchida-sensei turns Anzu down when she asks him out on a Sunday date, leading her to believe he's seeing another woman. When Hiiragi suggests they follow Tsuchida-sensei, Anzu, Hiiragi, and Koume unite to form the Hanamaru Detective Brigade.
Hiiragi and Koume follow Anzu as she chases after Tsuchida-sensei, but Koume trips. Just as she's about to break into tears, a boy extends a helping hand. The boy leaves soon afterward when his friends call him, leaving Koume to stand in the hallway by herself, unable to move.