GTO: Great Teacher Onizuka Vol 2

Former gangster Onizuka is ready to put aside his punkish ways and join the working world as a teacher. All that stands between him and a regular paycheck and dozens of hot girls to flirt with is the big teaching exam. Oh, wait, he accidentally used his study book as toilet paper! Now, without credentials, the only place he can land a job is at the Holy Forest Academy where he only barely gets hired after humiliating the Vice Principal. He'll have to use his street smarts to deal with students and faculty alike if he's ever going to become a Great Teacher.

Source: Anime News Network Encyclopedia