Brief Bags Japanese School Bags?

Japanese School Bags? - brief bags

I have tried to find a site or somewhere I can buy an authentic Japanese school bag / handbag.

We see much in the anime or pictures of the school in Japan.
The bags are usually black or brown leather (looks like a laptop bag), on a handle and can be turned on its back in a kind of backpack.

I can not find anywhere where they sell in order to be extradited to the United States if the products are authentic.

Any help would be very grateful!
Thanks in advance!
-DZERO