Yeong-soo saved money for 10 years since he graduated high school and now he’s getting ready to go to college, which he has been putting off. Ji-eun is his girlfriend who has been by his side for the last 5 years, but the sex with her is quite boring. It almost feels like a chore. However, he doesn’t want to break up with her, as they have been together for a long time. The first mock test comes up, but Yeong-soo has lost his will to go to college and his sexual desires. Ji-eun is not taking this easy either. She knows his sexual fetishes and thinks she can stimulate him, so she calls her elite friend Hye-ran to ask her to tutor Yeong-soo. Hye-ran becomes Yeong-soo’s tutor. Just like Ji-eun planned, Yeong-soo begins to feel animal-like desires for sexy Hye-ran and his will power to learn comes back. Meanwhile, Hye-ran begins to feel attracted to Yeong-soo, which is not part of Ji-eun’s plan. One day, Hye-ran seduces Yeong-soo when Ji-eun is not around…