100 years ago, titans suddenly appeared on Earth. Soon, human civilization veered on collapse due to the titans. Humans then built a giant wall to defend themselves. Within the giant walls, humans lived in peace, but, 100 years later, the giant wall is broken.
Description: Set in the world of competition swimming. Woo-Sang (Lee Jong-Suk) is a national swimmer. He pursues the number one spot. Won-Il (Seo In-Guk) is gifted swimmer, but stopped participating in the sport. He then makes a come back.