Suspicious about the relationship between Haruka and Yuu, Mitsuki asks their classmates, Yuzu Iizuka and Kaede Ikeno, to keep an eye on them and make notes any suspicious behaviour. Later, the girls get together for a test of courage, where Mitsuki attempts to tail Haruka and Yuu, but gets mistaken by Yuu for a ghost, leaving her so scared that she asks Haruka to kiss her to calm her down.

With the cultural festival approaching, Haruka, Kaede, and Yuzu go to a café with Mitsuki to try and convince her to join in their class' production of Snow White. When the others arrive, Yuu displays some displeasure in having been left behind at school, due to Haruka wanting to surprise her, but the two manage to make up with each other. Later, the girls succeed in coercing Mitsuki into playing the role of Snow White, where she becomes paranoid about being kissed by Haruka during rehearsal, only to realise it was only a speech-only play.

The girls decide to sleep over at school in order to complete their preparations for the cultural festival. During the nighttime, Shizuku gets to spend some time with Kotone, whillst Haruka and Yuu also have some time together. On the day of the festival, after a successful performance, Haruka goes around the festival with Kaede and Yuzu, where Kaede explains why she chose to become the class representative. Haruka and Yuu then spend the rest of the festival together, kissing all the while.

Kotone invites the girls to swim at her family mansion's pool, where they meet Kotone's little sister Shinobu, who seems determined to have Kotone return home. Shinobu challenges Shizuku to a swimming contest to decide who Kotone should stay with, which Shizuku ends up winning thanks to some meddling by the family maid. Later, Yuu decides she wants her own scarf, only to find the one she had her eye on had been bought by Shizuku, so Haruka goes shopping with her. They find the scarf Yuu wanted, only for her to choose a different one instead.

Haruka invites Yuu to join her in attending a relative's wedding, which Yuu misinterprets as Haruka asking her to marry her. Although Yuu is disappointed that this is not the case, Haruka becomes touched by the thought of it. On Christmas Eve, Mitsuki joins Haruka and the others in visiting the Christmas lights, noticing that Haruka and Yuu seem to be shying away from each other. After Haruka and Yuu become separated from the others, Haruka reveals she had been shy to look Yuu in the face because of the strong feelings she's been having, with Yuu replying she had felt the same.

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.