The story tells the story of high school student Seo Danai, a handsome and warm-hearted boy with excellent personality, IQ, and popularity. When he was 8 years old, his mother entrusted him to live in the home of Li Xiyuan, who was born only one day earlier than him. As a child, he was protected by Li Xiyuan, who looked exactly like a boy. When he grew up, he has been silently protecting Xiyuan. As a high school student in the same school, Han Yingbin has the legend of the God of Cupid, which makes many girls fall in love with him and rush to confess to him. However, he has never accepted any girl's confession, but unexpectedly he has to accept Xiyuan's "confession"! Xiyuan, who had been emotionally blank before, started a different high school life...
Although the beginning of things is surrounded by a lot of youth and embarrassment, that period of youth has a brighter romance than the summer spent.