よもさん(岡田義徳)が外れくじを引いたことにより、プール掃除の担当となってしまったプラモ部。少ない人数ではプール掃除が終わらないと危惧し、セトルカ(筒井あやめ)は軽音部、タカルカ(賀喜遥香)は玲(小林桃子)に助けを求めるも撃沈してしまう…。
そんな中、よもさんが発案したのは、部活対抗カーレース！負けた部活がプール掃除を行うというルールのもと、他の部活を巻き込んで真夏のプールレースが開幕！
When Yomo-san (Yoshinori Okada) draws the losing lottery ticket, the Plastic Model Club finds themselves in charge of cleaning the pool. Concerned that they won't be able to finish the job with a small team, Seto Ruka (Ayame Tsutsui) asks for help from the Light Music Club, and Taka Ruka (Haruka Kaki) asks for help from Rei (Momoko Kobayashi), but they are defeated... Meanwhile, Yomo-san comes up with the idea of an inter-club car race! With the rule that the losing club must clean the pool, the midsummer pool race begins, involving the other clubs!
