At the library, Kotonoha is seen borrowing a series of books titled First Love. While putting books away, Yuuki's colleague and sempai, Kyouichi Kasannoin, sees him handling the book and begins teasing him about needing it to help him with his love life, despite First Love being targeted towards girls. Yuuki retorts that it isn't his and that Kasannoin may need the book himself to pursue a girlfriend. The two quarrel for a moment about who needs the book more when Kasannoin begins to ask Yuuki about his taste in girls. When Yuuki refuses to answer, a horrified Kasannoin then asks if Yuuki likes boys, which the latter vehemently denies.
After Yuuki turns down his sempai's suggestion of looking for girls at his tutoring sessions, Kasannoin then points out a girl who catches Yuuki's eye on her way to the library entrance. Following the girl is Yuuki's older sister, Chie, who orders her younger brother to buy her some cake from Sweets Ohara.
After closing down the library, Yuuki and Kasannoin head to Gakuenmae, where Kotonoha bumps into the former while she is hurrying to meet Makoto Itou.
At Sweets Ohara, Yuuki meets Hikari Kuroda, an acquaintance from middle school who works there part-time. He also witnesses some banter between her and Mr. Katsura before the latter meets with the manager, Misako Toono. Yuuki then compliments Hikari on her adult manner before buying a cake set.
That night, Chie and her friends from the girls' basketball team, Ion Ishibashi and Youka Kira, along with the girl from earlier, come to Yuuki's room. The older girls then start smoking, much to Yuuki's frustration. He is then properly introduced to the girl, Roka Kitsuregawa.
Chie sends Yuuki for the cake and some tea, the latter of which Roka volunteers to help him with when Ion and Youka start pressuring her to take a puff. In the kitchen, Yuuki and Roka get to know each other better and agree to address each other by their given names. As Yuuki opens the cake set, he sees a card from Hikari. Later that evening, Yuuki walks Roka to the train station and the two exchange goodnights.
The next day, Kotonoha makes some mistakes when returning some books and Yuuki helps her rectify the mistakes. He then asks Kotonoha if she has a boyfriend, to which she answers yes, and Yuuki starts to ask her advice about how to start a relationship with a girl. While they are discussing this, Roka comes in and asks if she and Yuuki can have lunch together, only for Kasannoin to deny the request, as food is prohibited in the library.
After an interlude, Taisuke Sawanaga, another middle school acquaintance, invites Yuuki to have lunch with him outside school, which Yuuki refuses, not wanting to break the rules. However, he finds that the food in the cafeteria is sold out, so he goes back unhappily. As he passes by the courtyard, he sees Makoto making out with Sekai Saionji. Unaware that the boy is Kotonoha's boyfriend, Yuuki starts to think that love may be more than what Kotonoha has told him, as this couple seems to be following a much different style than Kotonoha and her boyfriend.
In the meantime, Kasannoin has started dating a girl from the basketball team, Nanami Kanroji, who is also Chie's rival. The team is also in charge of handling a traditional task at this year's school festival: the break room.
One evening at Gakuenmae, Yuuki witnesses Roka being bullied by Otome Katou, her former middle schoolmate and current basketball teammate who projects her issues with her womanizing father upon her. As Roka is about to get on the train with Otome, Yuuki invites Roka to get cake with him at Sweets Ohara. While the two have cake together, Hikari teases Yuuki about whether he is on a date with his girlfriend. Before Roka and Yuuki part ways, Roka gives her email address to Yuuki.
Eventually, Yuuki asks Hikari for her help, as things with Roka aren't progressing the way he'd like. She agrees to meet with him at Sweets Ohara, an exchange that Taisuke witnesses and leads him to conclude that the two are dating. Later that evening, Roka (accompanied by Chie, Ion, and Youka) comes to a similar conclusion after seeing the two there.
The next morning, Chie and Youka recognize Makoto (accompanied by Kotonoha), having seen him making out with Sekai at Gakuenmae a few nights ago. Yuuki recognizes Kotonoha and notices something familiar about the boy she's with.
While the classes make preparations, Roka approaches Makoto, asking him to accompany her to the festival.
The morning after, Yuuki tries to clear things up with Roka. However, when Roka asks Hikari's friend, Ai Yamagata, who the former is dating, Ai "affirms" that Yuuki is Hikari's boyfriend, noting that Taisuke had seen them together. Thoroughly frustrated, Yuuki goes to talk to Taisuke, only to meet Makoto. As Makoto calls Taisuke over, Yuuki recognizes the former not only as Kotonoha's boyfriend, but also the boy he saw in the courtyard with Sekai.
Later, at the library, Yuuki asks Kotonoha if she's dating Makoto Itou, which she confirms. He tries to tell her that her boyfriend is cheating on her, but she assumes that he's talking about "a girl from the basketball team who went to the same middle school" (Otome) whose feelings are unrequited. She goes to make prints for the festival and Yuuki wonders if he's mistaken.