I traveled to Germany from Japan on 2nd August 2020.
At that time Germany was implementing immigration restrictions on travelers from Japan except for with special reasons to prevent the spread of the disease.
For example, the people who had a residence quantification for a long time were allowed to enter Germany at that time.
I already had type D of VISA, but Germany didn’t show which type of VISA you should have to enter Germany.
So I was worried about if I really could enter Germany.
As the result the people who had type D of VISA could enter Germany in spite of immigration restrictions.
Of course I had to show my type D of VISA to a immigration officer, but also I had to prove the reason of immigration.
In my case the reason of immigration was to research at University. So I showed the admission invitation from my University to the immigration officer.
I had my VISA which would go out of date about 1 month later, so in addition to that I had to explain I could extend the date soon after entering to Germany.
If you have any questions about immigration before traveling, you can ask Bundespolizeidirektion Flughafen Frankfurt am Main from the E-Mail address.
Finally Bundespolizei judges if you can enter to Germany.
Bundespolizeidirektion Flughafen Frankfurt am Main
I would appreciate if this information could help you.