Atsushi finds himself hanging out with Risa and her friends again, claiming that it's because he's going to Heikichi Nakao's house later. While at a restaurant, Heikichi mentions to Atsushi that he has two tickets to see Umibouzu, Atsushi's favorite musician. Risa interjects excitedly and she and Atsushi briefly gush about their love of Umibouzu. Noticing how similar the two are, Nobuko suggests that they go out, but the two quickly dismiss the idea.
Upon learning that Atsushi is popular due to his participation in the basketball club, Risa--worried about losing their bet--desperately asks Nobuko to find her a group date, which ends poorly. She laments her misfortunes the next day, when Atsushi stops by to give her her Umibouzu ticket and a notice: the concert is on Christmas Day, which is primarily celebrated in Japan by couples.
While walking back from school, the two run into Mayu Kanzaki, who looks remarkably like Chiharu and was Atsushi's former girlfriend as well as his middle school basketball club manager. The two exchange pleasantries before parting ways. The next day, Risa asks why he broke up with her and he corrects her that it was Mayu who broke up with him, claiming that there was another boy she liked. Bitterly, he recalls that the other boy was over two meters tall, leading him to suspect that he was dumped because of his height and making him more self-conscious about it than ever. Risa, surprised to learn that Atsushi had a past like that, finds herself sympathizing with him. After school, Mayu waits for Atsushi by the front gate and tells him that the former members of the club are holding a get-together on Christmas Day and that she hopes to see him there, because she has something to tell him. Atsushi is conflicted, but Risa says she'll go to the concert alone and encourages him to go to his former club's meeting, rooting for him to start going back out with Mayu.
Hoping to hang out with Nobuko and Chiharu before the concert, Risa is disappointed to learn they have plans with their boyfriends on both Christmas Eve and Christmas Day. On the day of the concert, Risa finds herself waiting in a park with nothing to do. After tripping and scraping her knee, she imagines Nobuko and Heikichi, Chiharu and Ryoji, and Atsushi and Mayu having fun together, and begins feeling depressed. Unexpectedly, however, Atsushi has been running around looking for her. When he finds her, she asks why he isn't with Mayu. He says she can wait until next time, because he made plans with Risa first and he doesn't break promises. At this, Risa begins crying, to Atsushi's confusion. Because they still have time before the concert, he walks her to a pharmacy so they can take care of her knee.
After enjoying the concert, the two start walking back home and Risa thinks to herself that even if the two are a comedy duo, it's still Christmas, implying that romance might blossom between the two. However, this thought is cut short when a man, surprised to see Risa, runs up to her and hugs her, confusing her as well as Atsushi.