Soo-in is the world’s one and only female baseball player who can throw a 130 kph pitch. Surviving from a boys-only high school baseball team, now she faces another challenge to be in a pro team. Watching her not giving up her dream, a new coach CHOI tells Soo-in that it’s an impossible dream, not because of her gender obstacle but because of her physical limit. Instead CHOI suggests a new strategy; ‘if you can’t beat boys by strength, throw something that boys can’t hit; a knuckleball.’