Minwoo, a medical student, feels pure love for Dahye, whom he bumped into while riding his bicycle on campus. With Hyun-tae's help, they meet again and begin to understand and love each other. Around this time, Min-woo's father is hospitalized due to a stroke caused by a business failure, and her half-brother, who was recognized as her father's successor, flees to the United States and reveals the secret of Min-woo's birth. When creditors gather to harass his sick father, Min-woo tries to dissuade them, but then hits and injures an old man and runs away. Da-hye visits Min-woo's refuge and persuades him to surrender. After serving his time in prison, Min-woo hears from Hyeon-tae and Da-hye about his father's death. After that, he leaves Da-hye and sets out to find her biological aunt.