S1E03 Theoretical Dolphin Kick!/Plot

Haruka Nanase catches a cold from his swim in the newly restored Iwatobi High School swimming pool. The next day, while taking the train to school, Nagisa Hazuki again tries to entice Rei Ryugazaki to join the Iwatobi High School Swim Club, which he bluntly refuses. Gou Matsuoka proposes that the swim club join an indoor gym so they can practice swimming until summer, but due to its expense, they seek sponsorship from the school.

Miho Amakata reveals that they won't get sponsored until their club earns accomplishments in tournaments, but would still require a fourth swimmer. Nagisa informs Haruka and everyone of Rei's perfect candidacy due to his feminine given name. This prompts Nagisa to wait for Rei after practice, much to Rei's surprise and continues to pester him about joining. The next evening, while doing pole vault training, Rei's coach admits that his form won't improve unless he stops calculating his movements beforehand, much to his frustration. Gou informs the swim club that she has successfully scheduled a joint swimming practice with the Samezuka Swimming Club at their indoor pool, but that they still require a fourth swimmer.

The following morning, Nagisa meets up with Rei on his run to school and explains his reasoning for wanting Rei to join the swim club yet again, prompting Rei to relent and agree to a trial basis. At the joint Samezuka-Iwatobi practice, Rin Matsuoka gives Haruka and everyone the cold shoulder. Rei tries to avoid swimming in the time trials, but is forced to do so and, much to everyone's surprise, it is revealed that he can not swim. However, he marvels at Haruka's beautiful swimming form, realizing that Haruka swims with passion rather than calculation. The next day at his pole vaulting practice, Rei doesn't use calculation and falls. He approaches the spectating swim club and admits that he would like to achieve a form similar to Haruka's and officially joins the swim club while tasking Nagisa with teaching him how to swim.