Junji (Jang Hyuk) is a physical education teacher in the school. He is loved by his classmates because of his handsome appearance and cheerful personality. One day, Junji's student Yingen (Zhao Baoer) revealed her passionate love to the teacher, which made Junji feel very overwhelmed. Junji has been married to his wife Shuyan (Xian Yushan) for many years. As time goes by, the passionate love between them has turned from strong to weak, and their married life has gradually returned to peace. Yingen's appearance and her passionate and unrestrained personality ignited Junji's long-extinguished heart fire, making him recall the throbbing and sweetness of his first love. However, as time goes by, Yingen, who is pressing step by step, makes Junji realize that it is time to end everything. However, Yingen did not let Junji go. Instead, she turned her spearhead to Shuyan, regarding Shuyan as the biggest enemy that obstructed her and Junji's love.