Dear Teacher Yang

Renxing Middle School in Renxing Town, Nanxin City needed a teacher to teach mathematics. The principal of the school immediately issued a recruitment notice. Within three days, a female teacher came to sign up. This teacher was kind-hearted and wore a suit, but there was something strange about her. She knew martial arts. During her tenure at the school, she worked hard, but in the end everyone knew that she actually had a shocking plan...