Joon-ho, a 11-year-old swimmer who hopes to become an Olympic medalist, has a problem; he always records 4th place at all the swimming contests that he participates in. His mom who is more enthusiastic than himself in winning is frustrated. Hearing a rumor about a competent swim coach that other moms hush about, she stalks one of the moms for his contact and manages to hire him as Joon-ho’s personal coach. His records soon start to improve. But the badass coach who once was the most promising athlete on the national team before he had quit trains Joon-ho the only way he knows how; to use violence.