@Graywing that kind of clothing is perfectly typical especially in cosplay days. They can't work at least legally in oppai bars or such. I live in Japan so this isn't uncommon.
@luvicvis those places aren't 18+ only. Minors can work there, wearing that kind of costumes is fine in Japan. The only thing minors can't do in those stores is drink alcohol. (Legally that is. Many of them still do though)