If you speak decent Japanese, I'm betting there's several girls there that wouldn't mind the business. You might not get the youngest or best looking ones. I usually email them first to see if they are okay with foreigners.
If you don't speak much/any Japanese, I doubt they have someone there that speaks enough Japanese to book an appointment for you.
Moderate speaking skills, can hold a conversation but still overcoming grammatical errors. Listening skills are no problem, I just get overly self conscious speaking especially when calling a service for the first time.