RR Warning! Spoilers Ahead.. Big Big Ones
some screens from http://www.futureblues.com/gokusen/

Fighto.. ON!
This is GOOD!! Season 1(2002, 17%) is kind of reminiscence of GTO decades back, but it soon clears any disillusions of it. Season 2(2005, 27%, Best Drama) is too similar to Season 1 so it got kind of boring at one point budden the guys make up for it. Season 3(2008, 22%) was hailed the commemorative program for Nihon TV's 55th anniversary.
The storyline wasnt bad but they seem to be reusing the sequence throughout, i.e. Yankumi either had some juicy dream with her crush, gets awaken by her subs cos its getting late for school, or chancing upon her crush while on the way to school, gets into some argument with Sawatari Head Teacher/Vice Principal, suddenly appears when her kids are having some discussion, kids get into some trouble, she gets a call and goes running, appears at the crime scene dramatically, gave a beating to all the guys who bullied her kids, then gives some lesson thingy to the kids, a bit of closing, end of episode.
Maybe bcos I watched all 3 seasons at one go..
But its definitely watchable, with Yankumi's antics, cheesy sound effects, some gags, some wah-she-so-powerful and a bit of tears.
Yankumi

Ojou
Yamaguchi Kumiko, nicknamed "Yankumi" by Noda in Season 1 and it stayed with all her students throughout, was orphaned at 7 and stayed with her grandpa, who is the 3rd generation head of the Oedo Clan. Everyone in the clan wishes for her to succeed the title as the 4th generation head but she does not have any interest to head a yakuza and prefers to be a high school maths teacher.
However, as fate have it, she was assigned to the delinquent class from the start of her teaching career and her idealistic nature threw her into loads of dangerous clashes with the students problems.
And she's been running in ALMOST EVERY EP!

Dorky
Nakama Yukie did a great portrayal of the manga Yankumi, so much that it looks the same! Dorky, unattactive in school, strong and fearless when protecting her students, the "commanding" Ojou at home, she is superb! Little doubts on her claiming the Best Actress for the Television Drama Academy Awards with ALL 3 SEASONS!
p.s. I actually rewatched her in MR. BRAIN. Simply top-class thou she is just guest starring in ep 5 & 6, playing the fake-multiple-personalities-syndrome-affected Kanako who is just a sophisticated revenger.
Hai Hai! Little (OK OK I'm old enuff..) BIG fan here from SG!!~
Everytime Yankumi goes chasing after her kids who got into trouble, she'll make a dramatic appearance when she arrives. Superhero appearance, no less! HAHA!

Breaks Door to some crooked Financier/Yakuza's Office.

Appears in some dark warehouse with light shining behind her

Crushes Roof of some abandoned building
And when she goes into confrontation..

Taking off her glasses after removing the hair bands and throwing them aside
Makes me wonder 1) Why the glasses doesnt break with her throwing it on the floor and throwing guys all around next; 2) Why she can always find the unscratched glasses and hair bands after the fight? That's countless glasses she threw!!
and probably countless glasses she broke..

Then she'll be tossing her beautiful tresses (voted Most Beautiful Hair consecutively from 2007 to 2009) before and in-between fights.

And she does throw some mean punches! Often taking opponents much taller than her! (Her reported height is 160cm. I think she's probably shorter than that since everyone is towering over her.)

She defends Goda from Ogata. Yes. The other way round. Ogata was trying to revenge for Kazama who was in a coma after one of the clashes with Goda's crew.

Nakama Yukie is probably one of the rare Japanese actresses who can pass off a fight with great style and is comedic enough for some laughter, not forgetting that she has the distinctive beauty!! What a natural!
The Guys of 3D

3D of Shirokin Gakuen
From Left: Waki Tomohiro as Kumai Teruo(Kuma), Ishigaki Yuma as Minami Yoichi, Matsumoto Jun (Hana Yori Dango) as Sawada Shin, Oguri Shun (Hana Yori Dango & Hanazakari no Kimitachi) as Uchiyama Haruhiko(Uchi) and Narimiya Hiroki (Nana, Hachimitsu to Clover & Bloody Monday) as Noda Takeshi.
Only Kuma stayed throughout the series with his ramen store being a food treat for Yankumi and her students. Matsumoto Jun claimed the Best Supporting Actor for Shin's role.

3D of Kurogin Gakuen (The best looking lot of all!)
From Left: Koide Keisuke (ROOKIES) as Hyuuga Kosuke, Akanishi Jin as Yabuki Hayato, Hayami Mokomichi(Night of Zettai Kareshi. Yummy!!~) as Tsuchiya Hikaru, Koike Teppei as Takeda Keita and Kamenashi Kazuya (Ka-kun!!) as Odagiri Ryu.
Odagiri reappears in the movie as a fresh teacher out of school. Aawww, this series is simply yummy!~ Little wonder the ratings r the best! 32.5% on the last ep! HAHA~
And Ka-kun claimed the Best Supporting Actor for Odagiri's role as well!

3D of Akadou Kokou
From Left: Nakama Junta as Ichimura Rikiya, Kiriyama Akito as Kuraki Satoru, Miura Haruma (Bloody Monday series) as Kazama Ren, Takaki Yuya as Ogata Yamato, Ishiguro Hideo as Honjo Kengo and Miura Shohei as Kamiya Shunsuke.
Not much recognisable faces here, since most of them just started their careers.
Yankumi's crushes

Sawamura Ikki as Shinohara Tomoya (Season 1)
The suave and gentle detective of the Shirokin neighbourhood whom Yankumi was squashed into on the bus to school.

Tanihara Shosuke as Kujo Takuma (Season 2)
The teacher of Momo High School (Girls school) which is opposite Kurogin Gakuen who saved Yankumi from an imminent roll down the stairs of the overhead bridge while she was day dreaming.

Koizumi Kotaro as Natsume Seichi (Season 3)
The school doctor for Akadou High School who works in Natsume Hospital that Yankumi bumps into while on the way to school. If his surname sounds familiar to u, YES, he is the eldest son of the former Japanese Prime Minister, Koizumi Junichiro!
He is HANDSOME la~
Crushes on Yankumi

Kaneko Ken as Asakura Tetsu
One of the junior member of the Oedo Clan who stays in the Yamaguchi house and is often seen showing his displeasure (with funny faces) when Yankumi is daydreaming about her crush in front of him or physically with the crush.
He's quite cute actually, without his moustache, which he kept due to some promise with Yankumi or something similar.

Sakata Tadashi as Kashiwagi Yutaka (Season 1)
The police officer that follows Shinohara around, has claimed that Yankumi is her type and is often trying to attract her attention.

Azuma Mikihisa as Baba Seiga (Season 2 onwards)
The P.E. teacher of Kurogin and ends up in Akadou as well, citing that its fate that he'll meet Yankumi again after Kurogin closed down. He, has also declared that Yankumi is her type and is always trying to attract her attention as well.
Others

Namase Katsuhisa as Sawatari Goro
The Head Teacher/Vice Principal who is always STUCK with Yankumi (Season 2 by mistake and in Season 3, he pleaded with her to join him at Akadou). He is at loggerheads with Yankumi though, as he does not agree with the way Yankumi deals with her students and having a teacher run wild WITH the delinquents("I saw the whole of 3D & Yamaguchi running out of school!" or "Bad News! 3D is not at their classroom! Yamaguchi is not around also!").
He always has a teacher next-in-line following him around boot-licking and he's nicknamed Saru (monkey) by all the 3Ds.

Sato Jiro as Yajima Hosaku
The "boot-licker" of Season 3 who also starred in 33pun Tantei. His expressions are quite funny.
Tear Jerkers

Shin making his valectorian speech in Season 1.
This is freaking touching ok!

I was crying buckets here.

This almost got me. Yankumi is finally not Fighto-ON-ing with herself.
Funny

Ah-Lian-nified Yankumi
Yes, this IS Nakama Yukie. Posing as a delinquent to attract attention to herself in hopes of nabbing some robber whom Uchi mistaken as.

Akadou Kamen
I rolled up in stitches looking at this scene in the Season 3 special. See her left hand. SHE'S TRYING TO MAKE THE ENDS OF HER SCARF FLY TO RESEMBLE SOME HERO APPEARANCE!!! Funny like dunno what!


Funny until I kept laffing! Got super-hero-appearance-action somemore!

This is of cos in one of Yankumi's dreams again.
All in all, this is a funny show no less, with a bit of tears at times. Probably just try to forget that u have seen the same plot earlier and it'll be definitely good.
Or just watch for the cute guys!! & Nakama Yukie's antics! HAHA!!