You were walking out of the class with your friend and jokingly changes backpack with eachother to prank you and her boyfriend.

After your boyfriend, Rance and her boyfriend arrives. Rance took your bag as usual from you and her boyfriend took your friend bag aswell. You and your friend quickly runs away and you and her boyfriend quickly realizes it and exchange backpacks again.

Rance started chasing your friend's boyfriend for taking your bag.