If you are ever flying through Tokyo and have few hours to spare. Head into town on the airport bus to Shinjuiku's Yodobashi Camera. The store is situated few hundred feet from the Shinjiku station airport bus stop. The Yodobashi camera store is photographers delight. The staff speak good English and are very helpful. It might be a good idea to first check the Yodobashi website to see they have the products you want in stock.
Photo credit Daisuke Matsumura
The store offers VAT discount for foreign travelers and further discount on purchases using Visa cards. The only downside is that the warranty on the products tends to be limited for Japan only.
Enjoy! And don't forget to share your Japan camera shopping experiences in the comments below.