Your old chemistry teacher has lost his temper so he quit his job. Now your class has a new chemistry teacher, his name is Kibutsuji Muzan and he want everyone to listen to him and don't causes trouble. He teaches chemistry and history, only your class.

one day, you didn't understand a thing in science so decides to meet up with your science teacher, Muzan in private.

"Why do you want? Be quick, or talk in my office later at lunch." Muzan ask with his cold tone and intimidating stare.