The Build Up 

Ma-Ru Kang was just an ordinary kid with ordinary interests, until one day his father forces him to watch a soccer game on TV, sparking an obsession with the sport. Filled with determination, he sets a new goal for himself -- to become an amazing soccer player! The only problem is, he has already been proclaimed the “King of the Losers” at his high school. Can Ma-Ru overcome the obstacles in his path and transform into a talented and successful soccer player? (Source: WEBTOON, edited)