Cosplay ... Something in Akihabara
I'm not sure really what Cos Pria provides, because I don't know enough kanji. The flyer advertises an "otameshi" (trial) for 40 minutes, at 6500 yen. The four options below are for 60, 90, 120, and 150 minutes. I can't quite translate the text above that, mentioning maids, 2 people, or something similar to that. In the pinkish box are "packs" though I don't know exactly what they provide. Beneath that are options: something involving a camera, and a 2000 yen "cosplay" option which probably allows you to choose a costume... though I don't know if it's for you or one of the waitresses.
Cos Pria could be a dating club, which would include one-on-one time with a girl of your choosing for the prescribed time. There are also massage parlors, lap bars (where you pay to rest your head on a girl's lap), wannabe-idol performance clubs, and tons of other options. Some are legal, some are borderline, and there are a couple that aren't.
Edit/Update: I'm told this is a cosplay cafe. But the person who helped translate the card wasn't able to provide much more information than that. Most likely you get a girl to hang out with you for a period of time, and you have the ability to choose your own maid for an additional fee. The other information above basically seems to be about true as well.
Of course, there are plenty of cosplay cafes and restaurants. As far as cosplay goes, you can have maids in any different color of maid costume, in frilly short-skirted French maid style or long Victorian. There are school girls, vampires, girls in yukata, anime girls, and more. I've talked about cafes before, and one of my friends really wants to visit one so I might end up posting about another in the near future.
The best way to find a maid or cosplay cafe is to walk down the main street or one of the busy back streets in the afternoon and find a girl in a costume you like. Usually they'll give you a flyer and/or try to take you to their restaurant. Before entering, look at the flyer. If it shows prices like above, you aren't going to a cafe. You should ask for a menu before sitting down, too, if you're not too sure.
Keep in mind that you can't ask for a particular maid, and the one who dragged you in off the street will probably go back out to continue handing out papers. But then again, you may have saved them from having to be out in the heat and they'll get to wait on you, while some other poor girl will be outside with the stack of handouts.
I'm kind of curious as to what this place actually is offering. If you have any information, let me know. I couldn't locate a website online, though I found a blog.