Legally, I believe you are bound to do such.
Technically, I believe all derivative works are as such (including fan art). It's just companies know that it's generally a bad thing to not allow fans to be fans, so I don't think they really care as long as no profit's being made. You may be able to see what other people have done, if it matters to you, by browsing yourself and seeing if there's any similar things up. It may give you a feel for the uploading community.
Even in cases where profit is made, they may give some slack depending. You don't stop Comiket from happening, and I have yet to see an Artist's Alley raid, but that doesn't mean they won't issue cease and desists for other things. (In fact, they could if they wanted to, but we all know how that'll turn out.)
You honestly may be able to just pop it up without anyone caring at all, as you're not actively slandering them, you aren't making profit (I'm assuming), and you're doing it with the best of intentions. Alternatively, popping it up on the web is likely to not cause a stir, in my opinion.
(Not a lawyer.)