The girl Yūto already bumped into twice turns out to be Shiina Amamiya, the new transfer student into his class. The school swimming tournament is coming the following week, but while Shiina can do an arrange of other skills, swimming is not one of her strong points, so Yūto and Haruka help her prepare in the school pool, but Yūto's sister, and Haruka's sister and maids come along too. At the tournament, Shiina gets a leg cramp during the race and Yūto jumps in to save her, and he takes her to the infirmary. She was not seriously injured, and was more shocked than anything else; Yūto reassures her that she tried her hardest, and that is what matters.
夏休み直前に、裕人のクラスに天宮椎菜という少女が転入してきた。以前に何度か出くわしていた裕人と椎菜は、あまりの奇遇続きに驚く。快活で文武両道なためにあっという間にクラスに溶け込んでしまった椎菜だが、水泳大会があると聞いて尻込み。椎菜が水泳を苦手だと知った裕人や春香は、彼女に泳ぎを教えることに…。
유토는 길거리에서 우연히 두 번이나 부딪쳤던 시이나와 또다시 부딪친다. 우연이라고 치부해 버리기에는 너무도 신기한 느낌이 든 시이나는 뭔가 인연 같은 것을 느끼고 유토에게 급격하게 마음이 이끌린다.
