Im assuming the bank you have has checked the money and has cleared it? Does the funding have some sort of code to it where you can track a previous transaction with? Maybe someone you bought from is giving you a partial refund or something. It sounds to me it might be an automated system that can credit you back from some online website...like if you returned something or demanded additional conpensation?
It's probably paypal related and the result of something you purchased from China or Japan being deducted or refunded. I have stuff that shows up like that on my bank statements all the time from buying on ebay.