Maid Cafe

Hi all! I have a group of friends and I that have bought maid cafe tickets for this year for Anime Midwest. None of us have ever been to the maid cafe before and I was wondering if we have to make a reservation for a specific time? If so, where would we do that? I was also wondering if we have to spend extra money once we are actually there on the items or if that is included in the 15$ ticket? Thanks!