The female protagonist (Ye Ke) (freshman) was adopted by the male protagonist (Ye Wen) (freshman)'s parents. At first, the male protagonist only thought that he had a biological sister and kept causing trouble for her. When he saw the adoption agreement before the female protagonist, he slowly began to like her. However, the sister at the moment didn't know anything until her sister discovered the adoption agreement when she was cleaning the room...
Concept: ignorant love