Learning how to be a ninja is rather straightforward. Normally one learns from a personal master, or sometimes a dojo. But there are those that believe that learning the skills of a ninja can be made to look like a public school. After all, you call your ninja instructor "sensei", which means "teacher", so it's the same thing. Right. Calling the instructor "teacher" is about the only thing ninja training has in common with schooling. There are no written tests, homework, or grades.