Touching and feeling water has always had a special meaning for Haruka Nanase. At the last championship during elementary school when he swam in the medley relay with Makoto Tachibana, Nagisa Hazuki and Rin Matsuoka, he could achieve a new perspective he had never seen before.
Haruka Nanase agree to join the swimming club after a very long time, and together with his friend tries to mend old bond and win in the regional swimming tournament.
Haruka visits Tokyo to look for a place to live for when he starts his college life there next month. Coach Sasabe recommended a real estate agent to Haruka, but when he arrives at the agent's office, he meets an unexpected character. Aiichirō and Momotarō are considering what to give Rin and Sōsuke as a graduation present. As they try to think of something that might surprise Rin and Sōsuke, Momotarō wins a premium lottery. The Iwatobi High School Swim Club members plan a surprise party to say goodbye to Rin before he goes to Australia. But Rin happens to see Gou and Momotarō as they run errands together all around town for the party.
Haruka, who is attending college in Tokyo, meets Asahi again and reawakens his memories from his middle school years, including those of Ikuya. Makoto is working toward a new dream while he is in Tokyo together with Haruka. Rin has an unexpected meeting in Sydney.