Haesu and Jinheon have been friends since childhood, but Haesu is in a relationship while Jinheon is a tough star athlete who enjoys teasing her. After Haesu is rejected by her boyfriend Jeong-un, who feels she no longer excites him, Haesu is understandably heartbroken and seeks Jinheon's insight as a man. Unbeknownst to her, her emotional plea for reassurance will ignite a passion that could jeopardize their 13-year friendship.