Seeking the help of an expert who has read various novels and recommending the name of a novel.

In the beginning, a cousin named Zhu and her cousin were chasing each other. Then, her cousin knocked over a person. This person was the female lead and wore glasses. In fact, she was very beautiful and knew everything, but for some reason, she disguised her true appearance in school. That cousin was the male lead. The male and female lead had met each other when they were young. There seemed to be some kind of agreement. He remembered that at a school performance, the female lead wore ancient clothes, played the zither, and danced. She was very beautiful in the eyes of the male lead. The rest was very vague. I've been thinking about it for a long time, but I can't remember. Please tell me the name of this novel. I vaguely remember that it was called something like glass. What castle? I don't know if it's right or not