GDR and friendship do not always come together. The pre-democracy system in Germany (and Poland) has caused many friends-to-faux-amis-transitions when it comes to interpersonal relations.
Nobody tells GDR stories like German directors/writers do. The rawness of storytelling and various (well created) characters make this movie worth watching. I will not go into details of the plot, but if you had seen and liked Das Leben der Anderen and Barbara, you won’t be disappointed.