Have been using this JP Yonex bag for about a month.
All I can say is this bag is well constructed and with clever allocation of pockets. It's deceptively bigger than it looks. The material is standard backpack polyester with the shinny part made of PVC.
The main compartment houses two tennis racquets or 3-4 badminton racquets. The top compartment allows you to store fresh clothing and the side pocket allows storage of keys or small items.
The middle compartment allows storage of wet clothes, shoes etc. There's also a small pocket for storage of water bottle.
The bag is made in Taiwan. The straps are secure on the shoulders, however, there is no waist strap like a backpack. Therefore, there is a limit on how much weight you can carry on this backpack.