Do you have children who like Wonder Woman? Or, perhaps, are willing to use child-sized Wonder Woman items yourself (hey, I don't judge)? Get thee to a Pottery Barn!
The backpacks and rolling suitcase are small, but look at this pencil case and lunch bag! Those are perfectly valid for adults and adult-adjacents going back to school!
Pottery Barn Kids has a surprisingly great collection of branded stuff, including Star Wars and Marvel. I'm hoping I'll be able to get this in Canada. I need a new pencil case!