Mika becomes angry when she realizes that the relationship between Yūto and her sister is not progressing as well as she expected, so she forces Yūto out on a date with her to teach him tips to get in the right mood with Haruka. During their date, they go to a café, and catch a movie before running into Shiina, which makes Mika jealous. Mika drags Yūto to a kimono shop and the two are outfitted with brand-new kimonos before heading to the summer festival and watching the fireworks with Haruka, Hazuki, and Nanami who find them. Once school starts again, Shiina volunteers to be one of the organizing members for her class' participation in the upcoming cultural festival, and Yūto gets dragged in to work with her.

Haruka quickly leaves after seeing Yūto on top of Shiina, but when Yūto tries to explain the situation to her, Haruka says she understands, but ends up running back home. The next day during the school festival, Yūto finds Haruka to have apparently forgotten about yesterday, though Shiina is not so sure. Yūto confronts Haruka about yesterday again, but she tells him she does not want to hear what he has to say and runs off. Yūto runs into Hazuki as he is searching for Haruka, and she gives him so advice on how to move forward with Haruka. With Hazuki's help, Yūto finds Haruka behind the gym where he apologizes for yesterday and assures her that he will not leave her. Afterwards, the two dance by the tune of the music box Yūto gave her previously as Nanami, Mika, and Hazuki watch from the bushes.