A prequel to the 2013 Kyoto Animation series Free!.

The first novel is about sixth grader Haruka Nanase, who sets up a relay team with his childhood friend Makoto Tachibana, a cheerful junior called Nagisa Hazuki and a newly transferred student, Rin Matsuoka.

The second novel is set in Haruka and Makoto's first year at middle school, and tells about their experiences at the swim team along with two new characters, Ikuya Kirishima and Asahi Shiina.