Jae-kyung (Hyun Bin), who was born with a golden key, is a playboy. What he wants to do most today is to get an ID card, so that he can inherit his grandfather's huge inheritance. But the next day after he got his ID card happily, he learned that his grandfather stated in his suicide note that Jae-kyung must first get a graduation certificate from a mountain valley middle school before he can get the inheritance. Jae-kyung went to the remote mountain valley school designated by his grandfather, but he did everything he could to get the school to expel him, so that it would be much easier for him to get the inheritance. He fought with Mingzhi, a famous bully in the school, but the school did not expel him. What he didn't expect was that Mingzhi's family was very enthusiastic about him. Then he wanted to bribe the principal, but was scolded by the principal. He had no choice but to study hard. Jae-kyung's boring campus life was brightened by a beautiful classmate, she was the class monitor Eun-hwan (Lee Yeon-hee). On the surface, he hated Eun-hwan very much, but with more contact with Eun-hwan, he re-recognized Jae-kyung in life, and the relationship between the two deepened.