"Yoo Min-hoo, a left-handed pitcher once ranked among the top 10 prospects in the nation! While pursuing a orthodox career, an injury leaves him unable to use his left arm. He transitions to a more technical right-handed pitcher, hoping for another breakthrough, but fails. Waking up after losing everything, he finds himself back in the past, 10 years ago. His left arm unleashes a fastball, his right arm seamlessly wields breaking balls. This is the story of the ace's return to the past.