Sora asks Haru to take her measurements so she can have a uniform made. The next day Nao comes over to bring Haruka some mosquito repellent, since Sora is scared of mosquitoes, and then leaves almost immediately. The next day Ryouhei invites Haruka to the school rooftop to take a peek at the girls cleaning the pool. Haruka warns Ryouhei, though, not to peek at Nao, and leaves. Much later Ryouhei tells Nao that Haruka, “the prince she has been waiting for,” has a crush on her; but she thinks he does not like her. The truth is that something happened between the two many summers ago: Nao, trying to escape the noise of her arguing parents, ran to Haruka's house. At that time Haruka was sleeping at their veranda, and was surprised to see Nao on top of him with her clothes undone. Until now Nao feels guilty for what she did. However, Ryouhei, even Akira and Kazuha, is into the act of bringing Haruka and Nao together. They did so by making the two meet at school pool on a Sunday. When they were changing after the swimming lesson, Haruka rushes into the girls' locker room when Nao was scared by a black cat inside a box. The school supervisor hears their chatter, but the two were able to hide inside a box before he catches them. Thinking it was just the cat, he leaves. There, Nao gets to know that Haruka does not hate her, only that he was just surprised at the events of that summer day, dispelling her assumptions. Meanwhile, Sora shows her hatred of Nao, whom she thinks is the reason why Haruka has been preoccupied the past couple of days, at home on her laptop.
ある日、春日野家に奈緒が蚊取り線香を届けにやってきた。だが彼女は、幼馴染である悠によそよそしい態度を取る。それは過去に奈緒が強引に悠と身体を重ねたこと原因があった。過去を後悔しつつも、悠を忘れられない奈緒。そんな雰囲気を察してか、穹は奈緒に対して陰ながら嫌悪感を抱いていた。
一方、亮平は、悠と奈緒が親しくなれるよう、一計を案じて2人をプールに誘い出す。奈緒との距離に戸惑いを感じながらも、昔から彼女に憧れていた悠は、カナヅチを克服するためにレッスンをお願いする。
そして泳ぎ終わった後、女子更衣室で起きた事件をきっかけにお互いの気持ちを確かめ合った悠と奈緒は、自然にキスを交わすのだった……。
对悠来说，奈绪从以前就是个能够依赖的大姐姐，现在也是让他感到心动的存在。悠在久违多时回到奥木染后，因身边有奈绪陪伴着而感到心安，但是奈绪却对自己过去曾对悠做过的事感到懊悔。
Ryouhei beobachtet die Mädchen während der Poolreinigung. Dabei erfährt er, dass Haruka auf Nao steht. Doch Nao fühlt sich schuldig für das was damals zwischen ihnen passierte …
