All artwork belongs to their rightfully owners.
Stealing is not tolerated what- soever. If I find out that any of this fanart pieces had been used on your site without the artist's permission, then I will personally deal with you on my own time. If I find out that you've been using artwork from a Japanese fan page, then I will see to your site's demise. Stealing is stealing and there's nothing good about that. Artists spend their time drawing for their own enjoyment so that you guys have something to look at and awe at.