Plot/Story
Although Gokusen revolves around the yakuza, I wouldn't expect a heavy, intricate plot like Tokyo Crazy Paradise. Gokusen, in fact, has a lighter, but just as enjoyable plot, about the granddaughter of the Ooedo Clan, a famous yakuza group. This young woman, Kumiko Yamaguichi, wants to be a teacher, and gets a job at one of the most infamous high schools in the area-- Shiroken High School, teaching one of the worst classes in the school. The only problem is that she has to hide her connection to the yakuza, or else she might get expelled from the school.
(My plot summary kinda sucks, but yeah. You get the point XD)

Characters
The characters are overall well rounded out, and each one is interesting, with their own little quirks. Although there may seem like a lot of characters at the beginning, gradually we get to know all of them pretty well. Kozueko Morimoto also skillfully uses their different personalities to create a lot of great humor!

Drawing Style
It's kind of fishy, in my opinion, especially at the beginning. Still, it's okay; it just takes some getting used to (even more if you like the typical shoujo manga style.), but the plot more than makes up for it. Plus, gradually, the drawings get better, and she starts using more interesting backgrounds and formats.

Enjoyment
The manga is hilarious and interesting. I'm never bored when I read it! XD

Overall
It's a great manga, though the only turnoff might be the drawing style. It's funny and absorbing, though not too serious, and I really recommend it to everyone!