There's something especially fun at the gym. Noh Dong-wan looks like a 40-year-old although he's only 23. He has a crush on Joo-ri, a childhood friend who completely loses her mind when she drinks. However, Dong-wan isn't a man to her. Then one day, intresting things start to happen when a pretty female trainer appears at the gym where Dong-wan, Joo-ri and a yoga instructor work. Will Dong-wan be able to tell Joo-ri his feelings?