Are they being sold anywhere in the US? Are they being displayed anywhere in the US? I’ve not seen one on anything.
Here.
https://www.google.com/search?q=japanese+flag+design+clothing&hl=en&biw=1093&bih=521&site=webhp&source=lnms&tbm=isch&sa=X&ei=coiMVdmzKIucgwSB04GoAg&ved=0CAYQ_AUoAQ