Noble Game: Commoner's Heir

To save his gravely ill mother, a 17-year-old enters an elite academy's game: 50 commoners pose as nobles for a month to win $100 million or face 50 years of unpaid labor. Posing as a billionaire's heir, he survives sabotage and confesses at the finals, only for his real father to reveal he truly is the heir. His mother is saved.