This is Japan’s shady “JK” or “high school dating” business. (“Joshi kosei” means “high school girl” in Japanese, and the English initials JK are universally used here to describe the practice.)
Although some cafes like this are relatively innocent — those that employ high school girls must close by 10 p.m., which means the men aren’t too late getting home to their wives — there is a large part of this world that is not.
There are various levels of high school dating, starting with cafes staffed by underage girls and peep shows where high school girls sit behind a one-way mirror in their school uniforms, posing according to customers’ requests.
There is also “tour guiding,” when girls go for a walk with men, a walk that often ends with some kind of sexual service, and the straightforward “compensated dating” — being paid for sex.