I think using VPN will solve the problem
and don't choose english / american flag, just stick with japanase (use google translation when you need to translate, sometimes the translation its not good enoguh but its ok as long we still can access the DMM)
and I think the R18 is still not complete enough compare to DMM, what do you guys think ?
R18.com has the same digital content as DMM plus it use CDN to have faster download/streaming from overseas.
If you buy from DMM you will be downloading/streaming directly from Japan.