Qiao, an 18-year-old boy, loses his voice while delivering a eulogy for his late father. He runs away from the funeral and hides from his family. Between past, present and future, the young man recalls his relationship with his brutal and secretive father, who left him a passion for boxing. Ten years later, now an engineer, Qiao develops an AI boxer to help people learn boxing. Training with the AI day by day, Qiao begins to see a ghost.​​