Duan Jiaxu and Sang Zhi became acquainted because of a parent-looking incident at Sang Zhi School, and Duan Jiaxu has since taken Sang Zhi as his own sister and loved him. With Duan Jiaxu's graduation from university, the two were separated from each other, and because of some misunderstandings, their relationship was estranged. It wasn't until the adult Sang Zhi was admitted to Duan Jiaxu's city as he wished, and the two reunited. Under the increasingly intimate contact, Sang Zhi gradually discovered the source of Duan Jiaxu's long-standing pressure, and she wanted to protect this big brother who had always been good to her and regain the secret love buried in her heart. In the company of Sang Zhi, Duan Jiaxu slowly untied the knot, he really fell in love with Sang Zhi who grew up, and an innocent crush finally bloomed into a beautiful love flower, experiencing the growth of youth together, encouraging each other and supporting each other.