There are a lot of scenes in Japanese films and anime that hero and heroine carrying a school uniform bag, and also when you visit Japan you will have a chance to see students (junior high and high school students) carrying it. School uniform bag started in 1881 mainly made with cotton and hemp, in 1955 the trend started to move to leather. In 1990 a lot of school started to designate Boston bag type and move to liberalize bags. Recently, Nylon Boston bags are in the trend and the bag which you have seen. School uniform bag seems characterless but it's functional, light weight and durable (price differecne maybe depends on the price). And the most surprising students decorate boring the school uniform bag with unique stuff! If you have interest and want to try it's able to buy direct from Japan through Amazon.co.jp and Rakuten Global here under. If this is the first time see "How to amazon.jp" and "How to Rakuten on the right side. Buy may be don't need because it easy to do! Enjoy!
To help you to buy stuff direct from Japan through Japan's largest and well known online shop Rakuten and amazon.jp