The central pillar of "Hidden Love" is the successful culmination of Sang Zhi's long-held secret crush on Duan Jiaxu. The entire narrative is structured to make this journey as satisfying as possible. The story begins when Sang Zhi is 14 and develops an innocent crush on the 19-year-old Duan Jiaxu, her brother's friend. A key turning point occurs when she is 17; she travels to his city but mistakenly believes he has a girlfriend, leading to a period of two years with no contact where she forces herself to move on.
When they reunite, Sang Zhi is 19 and a university student, and Duan Jiaxu is 24. This is where the core romance truly begins. Jiaxu, burdened by his father's hit-and-run accident which left him in a coma and Jiaxu in debt to the victim's family, initially still sees her as a younger sister. However, after he is hospitalized for appendicitis, Sang Zhi's devoted care for him makes him realize his feelings have changed. He begins to actively pursue her, and they become a couple in Episode 17. Their relationship is tested by Jiang Ying, the daughter of the victim, who harasses them, but Jiaxu deals with her decisively by issuing a legal warning.
A significant conflict arises when Sang Zhi's parents discover their relationship and object due to Jiaxu's complicated family background and the debt they believe he still owes. Sang Zhi passionately defends him, and reveals to Jiaxu for the first time that she has loved him since she was a teenager, dispelling the lie about her 'online boyfriend' from years prior. The conflict is resolved when it's revealed Jiaxu has already paid off the debt and his comatose father passes away, removing the final obstacle. The series ends with Sang Zhi's graduation, where Jiaxu proposes on a beach in front of her family. The final shot is of Jiaxu in Sang Zhi's childhood room, finally discovering the jar of paper stars, the physical manifestation of her years of hidden love, bringing the entire story to a poignant and complete circle.