This question will be asked numerous times, however, we need much more Arado Senki [JPN] players so I will answer them as many times humanly possible
Currently, due to the fault of the chinese hacking this game and stealing accounts, Japan has LITERALLY BANNED the ENTIRE world..
HOWEVER! Thanks to originally Razon for the VPN and OuterRem for helping with confirmations and such, we have found a workaround.
http://www.onrpg.com/boards/62115.html (Setting up proxy ip to play games..)
That is a proxy that connects directly to a Japanese server. It will allow you to bypass the IP check.
There are also instructions on setup and a filefront download FURTHER down because the downloads right now are dead
If Filefront doesn't work, I'll happily send you my copy of the Japanese VPN installer.
One note worthy of being mentioned. Credits to OuterRem and the victims... You MUST (for now) have a router in order for this program to work.
Good luck
If it's about REGISTERING.. Just use World Lingo or a translation site.. Very easy to register