After graduating from high school, the motivated swimmers enthusiastically go on their futures with a goal to achieve. Haruka Nanase, now a student at Hidaka University in Tokyo, encounters across Shiina Asahi, an old teammate and buddy from his middle school days. As a result, Haruka's traumatic recollections of his middle school swim team reemerge, as this was a time when his attitudes toward swimming grew negative, leading him to abandon the squad. Haruka subsequently reconnects with his other middle school classmates, with the exception of Ikuya Kirishima, who still resents Haruka for leaving the team, causing it to split. Haruka resolves to improve his friendship with Ikuya despite their differences. However, he rapidly understands that making reconciliation with an old buddy is not a good idea.