Roman Griffin Davis as the 10 year old JoJo is so incredibly attractive that the movie is wonderful from the opening scenes. The "Heil Hitler" montage at the beginning shows clearly how a country was taken captive by Hitler. JoJo is ardently German, to the extent that he has a wonderful imaginary friendship with Adolf himself (played by director Taika Waititi).
I have to admit that my damn hearing made it difficult to understand everything. Usually I watch movies with closed captioning, but that was not available for this film, so I missed a lot, but still I got the gist of it. An ardent Jew-hater, JoJo finds a Jewish girl hiding in the close of his late sister's bedroom and began to learn that they aren't all as bad as he was led to believe -- they don't all smell like broccoli and don't all have horns, for example.
The relationship between the two grows and strengthens when JoJo finds his mother hung in the public square.
It's an entertaining film and easy to see why it was nominated for an Academy Award.