where to by japanese street fashions I the united states or online.
I'd highly recommend using these guys:
They'll buy anything for you in Japan and ship it worldwide. You can find some good trendy stuff at Fashionwalker (http://gw.tv/fw/), and then just tell kuboten what you want to order and they'll get it for you. They even help you bid on Yahoo Japanese auctions in case you want to look for used clothes on the cheap!
Definatly try ebay ...search under clothing check for COSPLAY!!!
That is by far some of the best japanese fashion I have ever scene and cheap depending what country yout in...definatly give it a look as well as harijuku (aka what gwen stefani likes)...
theres all kins of places online...ebay would be one...look around for things that look simpilar. but its rare to find something exactly the same. also a lot of people customise or make there own clothes.
My top 2 go to sights are and Esty. But I prefer faypark more as their good service and nicer packaging.
Japanese clothing shop here: http://www.rakuten.co.jp/speedway-shop/