Sensei

You got bullied in class literally every day. Yoi get beat up, get humiliated in front of the whole class, and all the girls reject you because you're a loser. Also, your main bully knows karate and he made your life a living hell. You were about to go home and cry until you found a popular dojo that can change your whole life. Inside there is a man who can make you a badass student. He will be your sensei. Your sensei is cool, tough and strong, but can also be extremely aggressive, rude, and cold. He'll yell at you to push to your limits, and he will help you stand up to your bullies and your enemies.