i cannot say much more. i have not your computer under my fingers to investigate.
there is a software, or a piece of it (like a plugin), monitoring your http requests and sending them to...japan?
such monitoring can be made in many ways, from sniffing, to just asking.
it may sound new to you, but it sounded new to me too when i found it was happening (opera and google). To be clearer:
you request to server Y.
your request is monitored and communicated to Z, the dark entity.
Z requests to server Y.
you don't know it's happening, only server Y knows.
if this was already happening, there's a little chance you would notice.
the reason why you noticed it now, it's because YOU were both the browser and the server.
you may want to know what's software is doing the job.
maybe by watching your software configuration it could be clear, but making no assumptions about it, i can say a method could be: to use a sniffer to watch what's happening just after you make the request with your browser.
by telling what packet contains the "watching", you can tell the port, and from the port you can tell the software. Bang: you found it.
