Is Rascal correctly wearing a real type of backpack?
I believe it's the same type of bag that the other students have, but he is wearing it on his back, wrapping his hands through the straps instead of holding it over his shoulder. 

User Gorzius illustrated this for us below!



I'll admit it looks slightly disproportionate in the photo from the opening. 



To answer your question then, I would say yes, handbags like this are real.