Do Hyun Jung  is a bodybuilder. He wins first place at the Mr. David Competition, which is the ultimate dream for all bodybuilders over the world. Then, Do Hyun Jung suddenly disappears from the competitive bodybuilding circuit. He takes over an old neighbourhood gym. As a gym owner and trainer, he struggles to make the gym a success. In his pursuit to have a successful gym, he recruits new members. Lee Mi Ran is one of them. She has never had a workout experience. She unexpectedly enters Do Hyun Jung's gym after a shocking breakup with her ex-boyfriend. She believes in the words of her passionate trainer Do Hyun Jung, who promises to change her body and her life. Soon, she faces an even bigger ordeal.