The episode begins with the introduction of Serina Kanno, a popular and charming student who has been the center of attention since the start of the school year. Uka learns from Ayumi that Serina and Kai were a couple in middle school, but their relationship suddenly ended. This makes Uka reflect on Kai's past and her own insecurities.

As the class prepares for the upcoming midterm exams, Uka suggests studying with Ayumi and Satoru. Surprisingly, Kai joins the group, which makes Uka nervous. During their study session at a café, Serina appears, accompanied by her friends, who mock Uka for her early curfew. Serina intervenes and defends Uka, further deepening Uka's admiration for her.

Later, Serina's friends apologize to Uka, and Serina explains that she doesn't want to abandon her group, even though they often cause trouble. Uka is impressed by Serina's strength and kindness but also feels insecure, believing that Serina is the one who truly suits Kai.

At school, Yuru encourages Uka to tie her hair into a ponytail, which draws attention. Kai compliments Uka's new hairstyle, leaving her both confused and happy. At the same time, classmates speculate about the reason for Kai and Serina's breakup, further unsettling Uka.

The episode ends with Uka volunteering for the cultural festival committee to gain new experiences and become more confident. She decides not to rely solely on her academic strengths but to actively work on feeling equal to Kai and Serina.