Kyoukasho ni Nai!  

Not in a Textbook!, 教科書にないッ！, Kyoukasho ni Nai

Tairaku teaches at a high school where many students behave poorly. Despite already having a difficult life, meeting a new girl will cause even more problems for him. His personal and professional relationships, including his crush on another teacher, will be put in jeopardy because of this one student.