Here:
http://wingnuts.sakura.ne.jp/Wingnuts/main/index.html Directions: Look to the left, click "Batman" and then click "Batman", "Titans", and "DCU_Marvels" in order to see all the galleries.
I love a lot of Japanese fan art. Trouble is, it's hard to *find*. When all the words are in kanji, and you only know how to search stuff in English, you're kinda screwed...