Wachenroder Fan Pages
There are a number of Wachenroder fan pages on the web and, surprisingly given the game was only released in Japanese and no translation patch has ever gotten far, there's several that aren't in Japanese. This is a roundup of the ones I've found.
A complete script translation into English was posted on GameFAQs by user gar3. The preface explains that his attempts to translate the game led to him meeting his wife! He reviewed the game and gave it 8/10.
Not exactly a fan page, but sculptor Heavy Gauge made several figures for the development of the game and posted pictures on his site. While the Lucian and Carol figures were featured in the manual and some animated sequences in the game (and maybe sold in limited numbers?), I don't think I've seen the gorgeous Bellebete figure anywhere else.
Some kind soul called Tanpoko posted all dialogue in the game in Japanese, which is invaluable for reference. (update 2016-12-19: At some point before June 2016 the site hosting this went down, and it seemed to not be preserved on the Internet Archive. Turns out that there was an issue with links but it had been archived safely, so the link above points to that.)
Someone wrote Wachenroder fanfic in English.
There is a light-handed but complete, helpful, and illustrated guide available in Japanese.
This site has a list of publications related to Wachenroder, including not only the strategy guide but also limited edition card sets from exhibits and coverage in magazines.
There is a German page with a review and a pile of screenshots with a little commentary.
That's all I've found, but if you know of anything else please let me know. Ψ