Cheng Qingyu is the grandson of Old Master Cheng, a third-year high school student who prefers staying home and playing games during winter vacation rather than exercising. He is overweight, with an obvious belly visible even under his down jacket. Cheng Qingyu is physically unfit, collapsing after only a quarter of a lap while jogging, compared to Shen Ge who ran half a lap before asking to slow down. He got through college physical tests by taking advantage of troubled waters, blending in with other boys who ran slowly. He is initially horrified when Chi Yi threatens to tell his grandfather about his slacking, feeling betrayed that his brother's friend would undermine him. He reluctantly joins Chi Yi and Shen Ge for jogging after his grandfather forces him outside.
