Gokusen is a manga series by Kozueko Morimoto. The story follows Kumiko Yamaguchi, the granddaughter of a yakuza boss and teacher at an all-male private high school. In 2008, an SP manga was out, featuring some of Yankumi’s (Kumiko) old students who are by now working adults.
In 2002, the manga was adapted into a television drama with Yukie Nakama in the title role. A second series was produced in 2005. The third season of the (live action) series was aired as Nippon Television’s 55th Anniversary Program in 2008.
A 13 episode animated adaptation by Madhouse ran on Nippon Television from January 6, 2004 to March 30, 2004.
A movie as part of the drama series was released in Japanese theaters on July 11, 2009.
The plot revolves Kumiko Yamaguchi, the granddaughter of a Yakuza boss, Kuroda of the Kuroda Ikka. Her parents died when she was at the age of seven, and her grandfather had no other descendants, so Kumiko is next in line to head the family business with the title of Ojou. However, her lifelong dream has been to become a teacher. While her grandfather approves of her choice, others in the family want her to become the next boss.
Kumiko becomes home teacher of class 4-2 in mathematics at an all-boys private high school where she is known as Yankumi. Her class is full of delinquents, but she tries her hardest to teach them not just academicly, but about lessons of life. Though she’s forced to keep her family a secret from the public, her Yakuza upbringing gives her the strength and the experience to reach out to her students, while also providing comedic situations.