Ruby, growing up a small town and now a top student at K University, had to take a part-time job to save her critically ill grandmother. Due to the manager's wrong room number, she accidentally walked into the room of Bill, a billionaire heir. After a night of passion, he mistook her for someone else, and she fled in a hurry. Thinking the secret would be buried forever, she was tricked by fate to become Bill's tutor and move into his luxurious hillside villa. He was an arrogant, pampered rich kid, and she was a stubborn, poor yet brilliant student. He tried to humiliate and seduce her to drive her off, but she threw him to the ground. "Want to get rid of me? Only if you graduate successfully!"