If you see IPs like 150.70.84.xx in your server log it could be that a visitor to your site has Trend Micro on his PC. If they have "Protection Against Web Threats" enabled you will see the Japanese IP number shadowing the page views of the user.

I think it's their protection against bad sites. When I first discovered this I was sure there was something really bad going on and wasted some time digging. I solved it when it dawned on me that Trend had been installed on my new Dell.