Joo Soo-in (Lee Joo-young), who used to be called a genius baseball girl when she was in middle school, still boasts a level of skills in high school, but not as good as before. Lee Jeong-ho (Kwak Dong-yeon), who fell behind Joo Soo-in until the middle school has become the ace of the team and is receiving the love call from the professional teams. But Soo-in doesn’t want to quit baseball here. Rather, she is desperate to become the first female baseball player to join a professional club. Her new baseball coach Choi Jin-tae (Lee Joon-hyuk) and her friend Jungho will be her assistants.