Yuu's older sister, Mitsuki, who has never met Haruka face to face before, ends up having her glasses broken due to Yuu. Meanwhile, Yuu becomes downhearted when she learns the sports festival is being downsized to a sports meet due to the school closing in three years, meaning she won't be able to do a cheering event. Wanting to help Yuu out, Haruka and the others join the meet committee to state their case to the student council, led by Mitsuki. Despite some initial failure, Haruka manages to build up the courage to state her plea to Mitsuki, who considers it. Later that day, however, Mitsuki comes across Haruka and Yuu in a compromising situation. Later, the girls get together to clean the pool, with Haruka and Yuu finding an opportunity to do some kissing in the pool storage.

Haruka and Yuu have a lengthy phone call leading up to the New Year, with Mitsuki also getting a brief opportunity to speak with Haruka. As the New Year rolls in, Yuu gives Haruka a kiss over the phone. Later, as Mitsuki becomes jealous of Haruka and Yuu linking arms with each other, she, along with Kaede and Yuzu, follow them to a park, where they almost catch them kissing. When Mitsuki trips up, Haruka manages to catch her, with Mitsuki inadvertently kissing her forehead in the process. Afterwards, Yuzu talks about her experience with learning to ride a scooter whilst Kaede laments the trouble she has with her siblings.

The graduation party for Mitsuki and Rina gets underway, with everyone giving them presents. During the party, as Yuu gets into an argument with Mitsuki over her kissing relationship with Haruka, Mitsuki, upon hearing that their kissing is part of a 'special friendship', confesses her love to Haruka. Following the graduation ceremony, Haruka is called about Mitsuki, who discovers Haruka knows nothing about love or dating and misinterpreted Mitsuki's confession. Haruka ends up rejecting Mitsuki, who leaves her with just a kiss on the forehead. Yuu, who had been watching them, bring Haruka to the old classroom, where they kiss whilst telling each other they love each other. With their feelings stronger than ever, Haruka and Yuu begin their second year of school.