It's true that storyline-wise, Mamizou's objects she uses are all tanuki. For the most part, however, she looks like she's pulling random objects out of no where. The main thing I noticed was that if Yukari was a hopeless masquerade character, you could give her all of Mamizou's animations and attacks with only slight modifications here and there and it would fit just fine (if you removed the tail, obviously). If someone were making an HM extension using Mugen and wanted to add Yukari, they could easily just take Mamizou and work off of that if they didn't want to make an HM Yukari from scratch.
Heck, even storyline-wise, she plays a similar role to what Yukari played in IAMP (IE, penultimate character that isn't helping the final boss with her schemes but reveals the final boss to the player).
Course, someone did say in another forum that in his opinion, Mamizou was basically Yukari but fun. The two really are pretty thematically similar, I suppose, using various substitutes to fill in the holes here and there (Mamizou using tanuki instead of teleporting in random objects, for example). Course, similarities among old wise sage-ish characters should be expected when I think about it.
