Yeah I was hoping it would be that easy, I have been able to make a DMM account through DMM.com but I am blocked from using anything on DMM.co.jp, this includes the main page as I can log in but that's all I can do before being re-directed back to this error screen.
Any page I try to access and even trying to access aigis through a direct link I am met with this message "This service can not be used from your area" which I thought was odd as I had heard DMM.co.jp wasn't region locked or it could be just my country blocking it (I'm Australian), reference pic below:
Reading up on it I can find a lot of people doing different things to get past this region lock (If it is a region lock) I have read some cases of it being on DMM.co.jp and DMM.com. I see some people didn't need a VPN as others just changed there cookies to get around this error but apparently it doesn't work for everyone (Like me) and your post has me scratching my head even more making me think I am doing something wrong.