My Good Enemy(2010)

Original title: Min bedste fjende

Sensitive 12-year-old Alf is the low man on his class' totem pole, and he's sick of it. Forming a secret, Machiavellian alliance with another student who also has grown weary of being bullied, he hatches a plan to throw a wrench into the well-oiled gears of the school social order. Everything seems to go according to plan, until Alf discovers that turning the tables on his tormentors has its own dire consequences.