Spoiler alert: This story is so uncomplicated that the title of this review is, in fact, a spoiler.
There are actually 5 seasons of Majisuka Gakuen. All of them center around a yankii (juvenile delinquent)school in which the students must carve out their place in the social structure with their fists. This is actually a pretty common theme in Japanese film, and it is probably the most ridiculous premise for a television show in the history of television. Majisuka Gakuen is unique as the story is about a girls only yankii school.
It is exactly what you might expect from that description with the exception of Season 3. 3 is an odd sort of alternative story line where the school is a prison. If you've ever wondered what the plot of a porno about a women's prison would be like if it featured psychotic, violent, teen angst without anything even remotely sexual season 3 will clear that right up for you. No matter how you look at it, season 3 was just a terrible concept.
I'm not sure off the top of my head who actually produced this, but Maisuka Gakuen is an AKB48 showcase. AKB48 is one of the most prolific Japanese idol groups around. There are around 100 members, and the girls take turns acting in each season of Majisuka. AKB48 is a singing and dancing kind of group. It's important to know this going in, because although some of the girls have done television and movies, for most of them this was their first taste of acting. There is a world of difference between Jpop and action movies. However, these girls are all pros. Every member of AKB48 has enough stage experience that Majisuka Gakuen winds up being an exceptional performance by a group of young women who are not really professional actresses!
I scored this as a 9 because it really is a brilliant example of the genre. I would say that even with the season 3 debacle, the overall quality of Majisuka Gakuen is easily comparable to the Crows Zero franchise.