He has not forgotten his first love for the past 10 years to Han Ji-Soo (Lee Yeol-Eum), a pretty and smart student who hides an inner pain from childhood. But he find a second chance, by an accident, he travels to the past when he was a high school student. There, he meets his younger self (Seo Ji-Hoon). Kang Shin-Woo struggles to make the younger Kang Shin-Woo’s love come true.