This app was mentioned in 13 comments, with an average of 1.00 upvote
Install this vpn (free) https://play.google.com/store/apps/details?id=com.northghost.touchvpn&hl=en
Select Germany as your location and search for the update, I've done that a few times, I live in The Netherlands.
Like others redditors said, use a VPN I'm using Touch VPN to watch the ads, after complete watching all ads I just close the VPN and that's it.
Use a free VPN: https://play.google.com/store/apps/details?id=com.northghost.touchvpn Or the Cloudflare DNS Resolver: https://play.google.com/store/apps/details?id=com.cloudflare.onedotonedotonedotone
Alternative solution: Download TouchVPN then go to Settings -> Apps -> Google Play Store -> Clear Data and then launch TouchVPN, change your country to United States and then access Google Play Store, it should direct you to the american version where you can download Sword Art Online: Integral Factor.
I've used TouchVPN to stream Pandora from not-USA. It's free and has no limits (that I know of).
I have no idea where it has servers though, apart from at least one in the USA.
May this app bring you eternal happiness...
Sorry something didn't work. Here's new link https://play.google.com/store/apps/details?id=com.northghost.touchvpn
Use a VPN. I use this one whenever I don't have access to a video.
I'm using Touch VPN