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.

春香の家出事件も解決して、今では春香と裕人の仲は、乃木坂家両親公認となっていた。だからといって、二人の仲がグッと進展したわけはなく、相変わらず一緒に部屋でお茶をしたり雑談したりという具合だ。そんな状況を見た美夏は、裕人のリードが足りないと断定。超絶奥手な姉のために、裕人に女の子との付き合い方を自ら手ほどきすることにした。その方法とは、裕人と疑似デートをするというもの。そうとは知らず、待ち合わせ場所で美夏からいきなり｢デート｣と言われた裕人はビックリ。そんな彼を連れ回す美夏だったが──。