Andrew has spent five years at Hogwarts. He is very comfortable at school, but not so peaceful at home. That's because he has a naughty sister who is four years younger than him. Andrew dares to say that he is a qualified brother. He always likes to share what he has seen and heard at Hogwarts, and he wants to teach her all the knowledge he knows. But to his regret, as his sister grew older, she became more and more annoying. She didn't like being lectured and always thought she could handle everything. Andrew couldn't do anything about her. But he didn't like the idea of ​​his sister gradually alienating him. So he would occasionally exercise his privileges as a "big brother" or do some small pranks. For example, when she deliberately ignored him on the first day of school, he secretly cast a spell to tie her shoelaces together. "Ah!" At the sorting ceremony, Andrew's sister pretended not to know Andrew. Then when she went on stage, she suddenly fell down for no apparent reason.