How much realness do you need? Seems some festivals deemed this had more than enough. And to be clear the central performances of the two lead actors is amazing - especially the female one in this. The male part is played by someone well known for his quirkiness - at least in roles. If he's completely different in real life, than kudos to him.
The movie overall has won a lot of prizes as imdb is stating, which is a little bit surprising ... at least to me. Can't be the script really, considering this plays a lot like an improvised experiment with some pillars set to give actors orientation. Feels like they're doing most, if not all of the work in that department. Which comes through in things being repeated and work place being ... well let's just say far removed from German efficiency ... or what people would imagine that to be. A lot of silliness going around and a strange love connection occurs ... an unlikely one some may say, but opposites attract so I would argue the opposite ... no pun intended.
If you are into German independent movies that are ... weird to say the least, this may be quite the experience for you. Everyone else be wary of what you let yourself into. This is not an easy watch. Some sensuality and sexuality included (with a bit of nudity)