The novel I recommend is Long Time No See, Doctor Zhou. The plot matches the description of the question. This novel described how the female protagonist, Su Xiaowan, fell in love with the male protagonist, Zhou Liguang, at first sight. However, Doctor Zhou was unmoved. Su Xiaowan tried her best, but she never succeeded. Until one day, she realized that she did not have her keys with her when she went to deliver food to her boyfriend, so she knocked on Zhou Liguang's grandmother's door. At this moment, Doctor Zhou was catching up on sleep at his grandmother's house. I hope you like this fairy's recommendation. Muah ~๐