Don't forget guys, that the term 'Otaku' is not a good thing to be called. I know America assumes that it's good, but it really isn't. You don't want tourists sneering at the business.
My Japanese History class had the class watch a show about Japan and anime. All these salary men were really embarrassed that they had been found out that they cosplayed or made doujin. From what my professor told me, the stipulation really came about in the 80's or early 90's when a serial killer was captured and found out that he had an obsession with some anime (I'm not sure which one). From then on, and it's faded out since from what I can tell, "otaku" was not a good term to be called.
How about rather than one or the other, you suggest the Paris Hilton route and have a Maid night each week? For each Saturday, the employees can dress as maids. That way she can have the normal, Parisian style bakery or whatever that she wants, and you can have the cosplay style. She might be more open to that idea or something. That way, if your workers are uncomfortable wearing a maid outfit, they can opt out.
If you're looking for decoration ideas, La Provence in Lake Oswego is a Provencal themed cafe with a large lavender field mural based off of the Provence region in France. It's got awesome break and delicious cakes. That might give her a few hints. It's pretty popular, too. They start baking at 5AM, though XD
I would go. Maids are so cute.
