As I am pretty interested in Balkan films for more years now and would say that the films dealing with war aspects are the most frequent topic for films of this region. However, this one is very touching.
Not sentimental or happy ending you should watch the alienation of the young hero who is touched by 20 days at battlefield where his best friend dies. After comeback home he cannot overcome such experience. He is alien for his friends and girlfriend, broke up with her and just wander around the streets... suddenly he sees a girl that he and his fellows found at the battlefield. Significant for her is a yellow cap that she wears... why yellow cap you must see the film itself to understand that.
The story of love and hatred in all possible ways, misunderstanding and unfortunately .. the war...The war that destroyed many happy families and countries themselves.
If you can understand the language then moving part of the film is also the main song performed by Ana Sofrenovic. I can't get rid of that song since I have seen this film. It is beautiful...
If I should recommend you dealing with the war theme, watch also the film Lepa sela lepo gore (Pretty village pretty flame). It is completely different film and much more cruel in some way but really unique.