[Be prepared for this very specific lesson on Japanese culture!]

I haven't been to the cafe myself but I saw the posting for it online. It's your typical cafe that serves hot drinks and snacks and things like that... But the servers are usually dressed up as maids and butlers. They serve the customers as if they're masters and will wait on them hand and foot.

[Izuku explains this like it's pretty normal. He doesn't know about the extra services that the cafe offers...]