Wow, a variety of artists are really trying to have Nezumi Marisa stick. But isn't Neko Marisa is better suited? I mean there have been more doujins with Neko Marisa.
Patchouli calls Marisa a "mouse" in-canon, though (mostly EoSD). She calls Marisa a mouse sneaking through the library, and calls Sakuya and the other guards "cats". See post #184614
Nekomimi Marisa is just people trying to throw cat ears on a character because they just feel like throwing cat ears on a character.
