I bought a new training bag in Japan last month.
I got the official サッカー日本代表 チームバッグ one, I really like it.
I bought it at Flagstown (inside the Football museum in Ochanomizu)
When I got it I was lucky, they were on sale, only 5 900 yen, and they only had a few left. I had tried to find it at the Adidas stores in Harajuku and Shibuya but no luck.
I really needed a new bag for my gym wear, my old backpack, which I have had for many years has now a broken zipper...
You can get it here Adidas store