Rentarou is walking home after rounding up a collection of Pentarou keychains when a group of boys attempt to rob him. A young woman intervenes to disperse them with a kendo sword, and as the thugs disperse, she turns her attention to Rentarou and—ZING!!
Rentarou begs Girlfriend #17 to let him repay her for rescuing him, and she eventually relents, with Rentarou treating her to lunch. At the restaurant, #17 recognizes Rentarou as one of her underclassmen, mentioning that she's classmates with Kusuri and explaining her great responsibilities growing up. After swatting Rentarou's hand away from her hair, #17 takes her leave, introducing herself as kendo club captain Kishika Torotoro before heading off to receive treatment under a bridge.
The next day, Rentarou drops by the kendo hall, where Kishika is in the middle of drilling with the other members. Noticing the boy walking toward her, Kishika suddenly loses her footing and stumbles into Rentarou before suddenly storming off. One of the members mentions that this is a routine occurrence for her, and Rentarou follows after her, finding her under a bridge petting herself with a fake hand and listening to prerecorded audio.
Being discovered causes Kishika to break down in tears, prompting Rentarou to comfort her. This in turn causes Kishika to melt into an infantile mindset as she confesses to Rentarou, who agrees to be her boyfriend.
Tropes:
- Made Myself Sad: Kishika expresses amusement that the head of the chemistry club looks like a grade-schooler before inwardly moping about the head pats Kusuri receives.
- Rescue Romance: Kishika's relationship with Rentarou begins when she saves him from some guys who were harassing him for keychains.
- Sherlock Scan: Kishika identifies Rentarou as her underclassman due to never seeing him among the third year students.
