Have you ever pretended you were good at sports to impress your crush? Enter high school student Oh Haemin, who desperately wants to catch the attention of Jeong Ina, recently elected president of the school swimming club. Ina is recruiting, and despite barely knowing how to float, Haemin somehow ends up making her think that he's an expert at the sport. Before long, Haemin has to prove himself in the lane. Sink or swim, it's time to make a splash!