- The heroine Lin Wei, 23 years old, is a librarian with a gentle and tough personality. She is longing for and alienated from family love because she was "abandoned" by her father in childhood. She depends on her grandmother Zhao Xiulan and lives in an old alley in a small southern town.
- The male protagonist Jiang Yi, 17 years old, looks handsome and harmless, but is actually deep-minded and possessive (yandere attribute). He was "adopted" by the heroine's father Lin Jianjun for special reasons. After Lin Jianjun's death, he entered the heroine's life as an "illegitimate son".
- Hidden thread: The heroine's father, Lin Jianjun, was an anti-drug policeman. He "abandoned" his family because his mission was exposed, and he was forced to cut off contact to protect his wife and daughter. He later died in the anti-drug operation; Jiang Yi is the orphan of Lin Jianjun's colleague Jiang Yong, who In order to protect Lin Jianjun, Lin Jianjun entrusted his comrades before his death to let Jiang Yi join his daughter as an "illegitimate son". This was not only to protect Jiang Yi (to avoid retaliation from drug traffickers), but also to hope that his daughter could get a "family" support.
