Dana is a warm-minded, active and sometimes a clumsy girl. Even though Dana is late for her first class in high school, she feels happy to be a friend of Je-Ah, a talented girl. As Dana gets to know Je-ah's misfortune, she also confesses her secret first love, In-woo, to her. Je-ah is so supportive and everything seems good for Dana until Je-ah agreed to date In-woo without a moment of hesitation when he asked. Moreover, Je-ah's cousin says Je-ah has changed because of Dana. What does he mean? And what are the mysterious dreams Dana always has?