Chidoriya World, I believe is the name of Chidoriya's website. They have some cute kanzashi from Chidoriya on Beauty Habit's website as well beautyhabit.com.
I know that Chidoriya is based in NYC, so there might be a stand alone store as well for them. Otherwise, there is Takashimaya on the pricier end and a Mitsuwa Japanese type mall/grocery in NJ who also have a website.
I've seen many hairpieces like the above on eBay as well.