GTO: Great Teacher Onizuka

Onizuka is a reformed biker gang leader who has his sights set on an honorable new ambition: to become the world's greatest teacher... for the purpose of meeting sexy high school girls. Okay, so he's mostly reformed. However, strict administrators and a class of ruthless delinquents stand between Onizuka and his goal and they will use any means, however illegal or low, to drive the new teacher away. Perfect, because Onizuka's methods won't be found in any teaching manual; he cares about the difference between legal and illegal activities about as much as he cares for the age difference between himself and a high school girl. So get ready for math that doesn't add up, language you'd be slapped for using, and biology that would make a grown man blush... unless of course, you're the Great Teacher Onizuka. Note: Episode 1 has an airtime of 48 minutes.</i>

Yu Yu Hakusho: Ghostfiles

Urameshi Yusuke, 14 years of age, is about as troublesome and violent as teenagers come. He is constantly ditching school, causing trouble, and getting into numerous fights everyday. One day however, he does the unexpected, sacrificing himself to save a young child. Such an action, was never ever expected, especially coming from someone as troublesome as Urameshi Yusuke. The afterlife is not prepared for Yusuke, as they never thought he would make such a sacrifice. Nowhere to go, and dead, Yusuke becomes a ghost and must earn his way back into existence. Yusuke is "employed" by Koenma, who is in charge while his father and ruler of the afterlife, King Enma, is away. Under Koenma's command, Yusuke helps to stop menacing demons that threaten the lives of people everywhere; whether by stealing priceless and invaluable items and destructive weapons, or by wreaking havoc on humans everywhere. Throughout Yusuke's journey, he is usually joined by; his arch-rival, and local bully, Kuwabara Kazuma. He is also joined by two demons named Hiei and Kurama, whom are ex-convicts of the afterlife that managed to escape from Koenma. This group of unlikely allies goes on to participate and struggle in battles that have outcomes that determine the fate of humanity! (Source: AniDB)

Beelzebub

Oga Tatsumi is a first year student in Ishiyama High, a notorious school for delinquents. One day he sees a man floating by, and the man suddenly splits in half to reveal a baby boy inside! (Source: Crunchyroll)

The Gokusen

Kumiko "Yankumi" Yamaguchi enters Shirokin High School to become a math teacher. She's assigned as the homeroom teacher for class 2-4, populated by a gang of delinquents. At first, the class tries everything to rattle her cage, but to no avail. In a short period of time, Yankumi gains the respect of the class. But what the school doesn't know is that she's the heir to the Oedo Group, a powerful yakuzan clan. So while Yankumi struggles to excel in her career as a teacher, she must also keep her yakuza background a secret. (Source: Media Blasters)

GOLDEN BOY

Kintarou Oe doesn't look like it, but he is a genius who completed all his university courses and then quit before graduating. He becomes a wandering student, going from place to place on his bicycle, seeking to learn what he can about life, the world, and women. He is willing and able to do any job he has to prove himself. His travels take him to a variety of locations and a variety of women, each who learns to love the hardworking guy, but not before he can run off. (Source: Anime News Network)

The Way of the Househusband

He was the fiercest member of the yakuza, a man who left countless underworld legends in his wake. They called him “the Immortal Dragon.” But one day he walked away from it all to travel another path—the path of the househusband! The curtain rises on this cozy yakuza comedy! (Source: VIZ Media)

The Way of the Househusband Part 2

The second part of Gokushufudou</i>.

Back Street Girls -GOKUDOLS-

A group of 3 yakuza failed their boss for the last time. After messing up an important job, the boss gave them 2 choices: Honorably committing suicide, or go to Thailand to get a sex reassignment surgery in order to become "female" idols. After a gruesome year long training to become idols, they successfully debut, with overwhelming popularity, much to their dismay. This is where their tragedy truly begins.