Ding Xiaoman, a 178-jin (89-kg) girl struggling with low self-esteem because of her weight, has endured years of contempt and bullying from the school's beauty queen, simply because they both like the same boy. Even Jiang Yi, the boy she secretly loves, treats her with disdain. After years of silently putting up with the abuse, she awakens the Ugly Duckling Boxing System. Through sweat and determination, she reshapes her body and earns beauty exchange vouchers by winning real fights. When the cool, strikingly beautiful new her steps into the boxing ring, her former bullies tremble and bow their heads. This time, she is no longer the timid, ugly girl.