Japanese films featuring school ijime (bullying) are as common as cherry trees in Ueno Park, and for good reason. When I was teaching at a boys' high school in Kodaira, western Tokyo, I would sometimes see signs of ijime, such as the returnee kid whose natively fluent English inspired titters from his classmates — until he stopped volunteering to speak. Or the quiet, timid kid who explained his bandages and bruises as the results of sports-club practices — until he stopped coming to school altogether.

But in facing a class of 40 rambunctious 15-year-old boys my first concern was less ijime than order. To keep it, I had to hold their attention with everything from jokes and games to, when all else failed, tossed erasers. (Though my usual target was the wall, not some miscreant's head.)

Yuko Moriguchi (Takako Matsu), the heroine of Tetsuya Nakashima's pitch-black drama "Kokuhaku" ("Confessions"), teaches a coed class of junior-high freshmen, but has given up trying to contain the chaos. Addressing them on the final day of class, she speaks evenly, slowly and precisely — while her talking, texting and otherwise occupied audience ignores her existence.