Update: Pearl Abyss has confirmed that the game requires an internet connection for initial setup (day 1 patch). Once installation is complete, the game can be enjoyed offline. However, an internet connection will be required every time they release a patch, the game will not run otherwise...
A lot of people down voting you don’t know how comedically bad the internet situation in Germany is.
I understand, when I first learned of it I couldn’t believe it either.