Can you take a camera backpack into stores in Tokyo?

Not a problem at all, but a lot of stores will get very uptight if you start taking pictures inside it.

I am sorry if i misunderstood your question, but if you're asking if you will be thrown out of a store in Japan because you have a bag on your shoulders and a camera with you, then the answer is absolutely no! If you did nothing wrong you will be treated very nicely in Japan :)

Most people in Japan carry some kind of camera, phone with a camera, a computer with a camera, or all three! Repair shop reception, where people bring items in need of repair is usually in the store too, so people bring all kinds of electronics with them.

I have been in Japanese stores with my small video camera many times, because actually i didn't know how to use it properly, so i asked them and they taught me what to do.

Relax and have fun in Japanese electrical appliances stores as it can be an awesome experience! My favorite shop is called Bic Camera chain store, you can apply for a points card at the register (just tell them your name and address) if you decide to buy anything, it will give you like 10% of what you paid as points, which you can use just like real money immediately during any next purchase. All the best!

http://www.japanmylove.com/