Hi Friend,
What you want to do is look into some VPN solutions. This is most likely the way to get the best ping possible.
I live and work in Asia and play on the US servers. Without a VPN I get about 300-400ms. With a VPN I can bring it down to 170ish which isn't awesome but it is okay.
Japan to US servers you would probably get 100ms without a VPN to Europe though...not sure but good luck.