For the 2009 film, Yankumi faces her toughest challenge yet. She must guide a new batch of delinquent students at Akado High School while dealing with high-stakes trouble involving her former graduated pupils. The Iconic 2009 Cast Breakdown

However, I believe you might be referring to the live-action film "Gokusen: The Movie" released in 2009. The movie is a Japanese action-comedy film directed by Masato Harada, based on the manga series.

For two weeks, Ryuichi was a ghost. He answered questions correctly but never raised his hand. He ate lunch alone, reading a dog-eared paperback on corporate law. He avoided the rooftop, the gym storage shed, and all the usual haunts of Shirokin’s petty bullies.