Hey there! Got some more goodies! ^_^
I was surfing and came across the official Japanese NIS site:
And, from there, I was able to access the Japanese sites for all 3 Marl games!
PPOMK: http://nippon1.jp/consumer/marl_kingdom1/ [I'm warning you, don't use Google Translate to read Marjoly's page. It's not nice! >_<)
Little Princess: http://nippon1.jp/consumer/marl_kingdom2/
Tenshi no Present: http://nippon1.jp/consumer/marl_kingdom3/
BONUS! The sites for Marl Jong and Marl de Jigsaw!
MJ: http://nippon1.jp/consumer/marl_jan/frame.html [The Japanese characters for this site are all screwed up, though, so you can't translate it >.>. You should still be able to access some of the features, though.)
MDJ http://nippon1.jp/consumer/marl_jigsaw/ [This site has some wallpaper downloads. Go nuts! You can also find some Fansite links, which is pretty cool. Wish the American branch of NIS was this cool.]
On the Nippon site, you can also find a full list of games that Cornet and Marjoly have appeared in. Pretty useful, huh? ^_^