A foreign instructor, Kain, was hostile toward Gu Nan Ting. Gu Nan Ting focuses on the lesson without paying attention to him. Before the walkaround, Song Song tells Cheng Xiao to apply sunscreen. Therefore, both of them were punished by Gu Nan Ting during the lesson. Although Cheng Xiao hates how Gu Nan Ting conducts his teaching, she serves her punishment and invites Song Song to do revision with her after class. (Source: Viu)