A euphoric beach outing having the dysphoric prologue of Kana being carsick is reflected upon warmly by Uchida and Yoshino who have taken the whole experience in stride. Yoshino remarks that Chiaki has become attached to Fujioka as an elder sibling in much the same way that Kana has with Uchida and her. Chiaki's exhortation for the whereabouts of her teddy bear disrupts the reminiscence; fortunately, Fujioka brings it back and Kana successfully obfuscates her role. Maki tempers her disdain for her summer homework by successfully wielding Fujioka's computations as her plaything until Kana and Chiaki extinguish her machinations. The next arc features Uchida having a near-complete computation crash as she struggles to complete her summer homework without Chiaki's counsel as the penance for abusing Chiaki's goodwill. Fortunately, Chiaki is not heartless; she eventually relents after seeing Uchida and Makoto's demonstration of interdependence being a two-way street. The final arc features Kana's attempts to forestall the approaching autumn backfiring upon her as Chiaki, galvanized by all the pranks Kana played on her, retaliates by eating Kana's dinner in addition to her own.
海に行った思い出話をするハルカ、カナ、内田、吉野。
だが一人、その輪にいないチアキはふじおかを探しているのだった。
「海に持ってっただろ。忘れてきたんじゃないの?」というカナに「持ってったけど、袋から出してないよ」と言うチアキだったが……