They sell it at a store here in Long Island, NY called HanNari. It's a lil japanese furbaby clothing/supply shop. They have other ones as well. Like mushroom, apple, beehive w/Winny the Pooh on the side. I was planning on getting Sango & Vash one as soon as I've extra cash to burn.
They don't take orders online but they have such cute things!
http://www.creativeyoko.co.jp/hannari/top.htm