Yamaguchi Kumiko Our Heroine. She is a 23-year-old college graduate, and is newly hired at Shirokin Gakuen. She is very idealistic, and wants to inspire her students and help them graduate high school. For the last 7 years, after the death of her parents, Kumiko has been living with her grandfather, who is the head of an influential Tokyo Yakuza group. Despite this strange upbringing, and the bizarre mannerisms she has picked up from it, Kumiko is a good-hearted girl who has a strong faith in her students, even when they think the world is against them. Her belief in them (and her kickass fighting skills ^^;) help her earn their respect. They give her the nickname "YanKumi"
	Sawada Shin 18 year old SAWADA Shin is the leader of class 3-D. He is cool, level-headed, smart, and somewhat introverted. He has the highest grades in the school, amazingly enough. Everyone in the class looks up to him (though they can't match his grades ^_^) Shin is feared because of an incident back in middle school, where he punched out a teacher. In the drama, Shin develops an interest in Yankumi after her finds her cellphone one day. He keeps an eye on her. He knows right away that something is not normal about their new teacher. In the drama, Shin has a very strained relationship with his parents that YanKumi helps him with. He also has a younger sister. I am not quite sure if he has the sister in the manga.
	Kumai Teruo Large and tough, Kumai (called "Kuma," or "Bear" by everyone) always seems to be getting into trouble. He's either getting into fights, or being accused of theft, or being attacked by a rival school. In the drama, Kuma's parents run a noodle shop. In the manga, Kuma's mother works at a hostess club. In either situation. Kuma has conflicts with his parents. YanKumi helps Kuma through some tough times. Kuma and Shin are best friends. They grew up together, and Kuma calls Shin "Shin-chan".
	Uchiyama (Uchi) Haruhiko Talk about a difference in looks between the manga and drama! In the manga, Uchi is pretty scary looking. In the drama he is really cute ^_^ He usually has his hair partially bleached, with his roots showing, and all pulled back in little hair clips or a headband. I tend to think of Uchi as the 2nd main student after Sawada. In the drama he is pretty cool, but has had some problems with his mother that Yankumi helps him with. He is also accused of being a purse-snatcher. Poor Uchi is condemmed simply because he is from class 3-D. Yankumi goes to amusing lengths to help Uchi out. He also gets a little romance going in the Gokusen spring special. Uchi in love is really adorable ^_^ Something else I find amusing is that in the drama, the bully Uchi is played by the same guy who played the bullied little student boy Noboru in the GTO drama.
	Noda Noda seems to have a larger role in the drama than he does in the manga. He has a huge crush on the sexy new English teacher. He always wears very colorful scarves around his neck, and after he graduates, he wants to go on to some sort of clothing design school and become a designer. In the spring special, Noda has some conflicts with Yankumi and class 3-D over the graduation ceremony and final exams.In the manga and anime, Noda is very different. He is a lot more tough, and deliquent. He is the one who came up with the nickname "YanKumi".
	Minami A ladies man! Minami always seems to be chasing after high school girls, and can often be found chatting on his cellphone with them or trying to get their numbers. With the way he looks in the manga, I don't think he would be that popular with the girls ^^; Minami faces a crisis that may prevent him from attending the high school graduation ceremony with everyone!
	Shinohara In the drama, Shinohara is a handsome, suave police detective. Kumiko meets him on the bus while running late on her way to school one morning. Because Yankumi's students are deliquents, she sees a lot of Shinohara at work. He is an all-around nice guy but seems slightly oblivious to the huge crush that Kumiko has on him. In the manga, Shinohara is the lawyer that works for Kumiko's Yakuza group. He's handsome and cool. Kujmiko's grandfather helped Shinohara back when he was a law student, and Shinohara works for the Yakuza to repay the favor. Kumiko has had a crush on him for a long time in the manga.
	Fujiyama-sensei Fujiyama-sensei is another female teacher hired by Shirokin Gakuen at the same time as YanKumi. In the drama, Fujiyama teaches English. In the anime she teaches music. Fujiyama is very sexy, and likes to wear revealing clothing. All the students love her. In the drama, Fujiyama wears her normal clothes all the time, but in the anime and manga she wears a tracksuit (a tight one ^_^;) like YanKumi does. Fujiyama used to teach middle school students, and is very happy to be teaching at a high school. She jokes about which boys are cute, and who she would sleep with. (But would she really sleep with them? Heh, I don't know ^_^) In the drama, Noda develops a big crush on Fujiyama, and is shocked when he discovers a secret life she has.
	Nakashima-sensei Nakashima-sensei is the school nurse, and is a character that only appears in the Gokusen drama. She is played by Nakazawa Yuko, a former member of the hugely popular idol group Morning Musume. I think Yuko does a great job in this role. Nakashima-sensei is fashionable, smart, and confident. She is also interested in Shinohara. However Nakashima is very friendly towards Yankumi, and is more of a supporter of Yankumi than Fujiyama-sensei. Nakashima does have some personal family problems that crop up later, involving her stepson. Not that long ago Nakashima was married, but her husband passed away. Yuta, her husband's young son from his previous marriage considered Nakashima his mother. This is something she has yet to come to terms with.
	Koucho (School Principal) Now this is an interesting guy. The school principal is the only one who knows about Yankumi's unusual background. He encourages her to keep it a secret because the PTA and the media would cause touble if they were to find out. In the drama, the Koucho stays on the sidelines, letting the Kyouto (Vice-Principal) run the school. Koucho would rather bo out in the school gardens tending to the plants. However he does have a great knack for popping up suddenly at unusual times to point out useful information. In the manga and anime, the Koucho is this happy little bald guy who likes to wear bow ties. Yeah.. he's strange...
	Sawatari Goro Kyoto (School Vice-Principal) The School Vice-Principal is Yankumi's main nemesis amongst the school staff. In the drama he is always blaming Class 3-D for all of the various crimes and problems that pop up. However it is often times HIS mistake that caused the problem. The Kyoto can be a good guy though, and even though he opposes Yankumi so often, there is sort of an interesting challenging rivalry between them. As shown in the picture here, he often goes nose to nose with Yankumi, making faces at her. The Kyoto is a married man (his wife seems to strike fear into the hearts of the rest of the staff) but he has a habit of hanging out in hostess clubs flirting with the girls there. In the manga, the vice-principal's role is very minor. I think he is actually shown only once or twice. His role in the drama is MUCH larger. And apparently everyone liked it a lot because in the anime that followed, they added the Vice Principal character, and he seems to be based on the drama version. (He even drives the same yellow VW bug ^_^)
	Grandfather In the drama this guy seems way too nice to be the leader of a Yakuza group. Really, you'd think he would be rough and vicious. Instead they portray him as this kindly, wise old guy who loves Kumiko very much, and is always there to support her and give advice. I have no idea how this character became Yakuza. I can see him as a company president, or fish market seller or something, not a criminal. Nice actor in this role! In the manga, Kumiko's grandfather is less cuddly-grandfathery, and more business-like and dangerous. More like the type you'd expect to see heading a Yakuza group.
	Tetsu Tetsu is one of Kumiko's lackeys. He is a member of the Yakuza group, and is very devoted and protective of her. He and Minoru always keep an eye on Kumiko and do their best to help her when they can. I think Tetsu has a crush on Kumiko, but he has no chance of winning her. He is more like family to her. I have no idea why they did this, but in the drama, the actor playing minoru looks like the manga Tetsu, and the actor playing Tetsu looks like the manga Minoru. Go figure.
	Minoru Along with Tetsu, Minoru is a member of Kumiko's Yakuza group, and is one of her loyal followers. He and Tetsu watch over Kumiko and worry about her. Minoru and Tetsu can occasionally be seen running a takoyaki stand near Kumiko's school where they can be near her if needed. Sometimes their enthusiasm in serving her almot betrays her secret, but all they want to do is help.
	Oshima Kyotarou Kyotarou is a manga-only character. He is a tough-looking member of the Yakuza, but he is really close with Kumiko. Whe he was younger, and Kumiko was a little girl, he taught her how to fight and defend herself when she was being bullied in school and teased because of her Yakuza connections. I like Kyo a lot. He looks really tough, but he really cares for Kumiko, and seems to cry a lot ^_^;
SEASON 2
	Yabuki Hayato Similar to Sawada in series 1, Hayato sits in the back of season 2's class 3-D. He appears to be the leader of the class gang. He is generally quiet and distrustful of everything but he has a quick temper. The other students in the class obey his orders. Hayato used to be friends with Ryu, but they had a falling out. Hayato's homelife is strained. His mother died when he was young. He does not like Yankumi very much at first, but begins to understand how great she is as the series progresses.
	Odagiri Ryu Ryu comes from a wealthy family, but he is not happy at home. His parents divorced when he was young, and his mother has remarried. Ryu does not get along with his step-father. When Yankumi first meets Ryu, he is working at a night club. Ryu quit school over his fight with Hayato and hasn't been back in a month. At first he resists Yankumi's attempts to get him back into school, and he even cruelly tricks her. But he eventually gets some sense and listens to her a bit. He is still wary of her, and always sits in the back of the class observing everything that goes on. He is calm and quiet. I think if you merged Ryu and Hayato together, you would get Sawada from the first season ^_^
	Takeda Keita The most sympathetic character in the new class 3-D. He has been friends with Hayato and Ryu for years, and doesn't like that Ryu was not coming to school and that they were fighting. He shows signs of understanding how hard Yankumi works to be a good teacher and can tell right away there is something different about her. In general he is more sensitive than the rest and even has a crush on a girl from the neighboring school. He also seems to have inherited all of Uchiyama's cute hair clips ^_^ They always do funny things with poor Keita's hair.
	Tsuchiya Hikaru Tsuchiya Hikaru is the really tall guy in Yankumi's class. He is always shown carrying a paper fan. Tsuchiya has a tough, short-tempered personality that tends to get him in trouble. He is the first one to really pick on/test Yankumi when she first became class 3-D's teacher. However Tsuchiya is quick to defend his friends. He had some trouble with a teacher when he was in middle school, so he dislikes authority. He has some problems that Yankumi helps him with when he is caught after school with a middle-school girl that he was trying to help.
	Hyuuga Kousuke Hyuuga doesn't get that much screen time compared to the other guys in the main group, so I am not exactly sure about his personality. He always wears a stylish shirt under his school uniform, and he seems interested in making money. His family life is strained, and he ends up getting a job in a bar/host club, working for some very shady people. Fortunately he has Yankumi for a teacher!
	Kujou-sensei Kujou Takuma is a teacher over at the girls school across the street from Kurogin. He catches a falling Yankumi one day, and she instantly became smitten with him in a way similar to what happened with Shinohara in season 1. (I have no idea what happened to Shinohara ;_;) Kujou is friendly, and is somewhat oblivious to Yankumi's affection, though not as bad as Shinohara was. Kujou has some sort of clue, and even gets to see Yankumi in action saving a student. He cares for his own class, and wants to become a strong teacher like Yankumi.
SEASON 3
	Kazama Ren One of the leaders of Class 3-D. Was helped by YanKumi when he was accused of being a purse snatcher.
	Ogata Yamato The other leader of Class 3-D.
	Honjou Kengo
	Kuraki Satoru
	Ayukawa Sakura The school nurse.