Picking up international mail in Okinawa

Hi everyone. I stupidly left some documents back in Europe that I need to pick up whilst in Okinawa. I want to get these documents sent by airmail to Okinawa, to be held for me until I can collect it. Does anyone know if such a service is available, and how to go about it?

I would be extremely grateful if anyone could help me with this 🙂

by ImperceptibleFerret