Since they don't serve food or drinks, I don't think it's a concept cafe. You're free to bring your own, so if you want to eat or drink, you can bring something along. The interior is divided into several booths, and it seems you can play games too if they're available. It seems decent for chatting about various things. Apparently the first visit comes with a substantial discount.

A nice space where you can chat and play games with cute maids and feel right at home. It's also nice that you can bring your own food and drinks.