Seorin Jung is an ordinary freshman in highschool. And as the daughter of the school's soccer coach, she often comes to practices to watch the players and comes to every game to support her one and only crush- the popular senior and soccer captain, Byunghun Lee. He's been playing soccer ever since he was little, it's basically his life. 

However, one day during practice, Byunghun trips and ends up breaking his right leg. Seorin comes and visits and discovers something that she's always been dreaming of...