I saw this film about 13 years ago, so I don't know if all the details are here or if I'm getting them right:
I believe it was a Polish film (I saw it in Germany, though), black and white, where a girl had to wear black because someone in her family had died. She was friends with a boy and at one point, they were in the woods and she thought that a bug had gone up her skirt, and so he tried to find it, and it turned out to be a twig. The boy also was friends with another boy who didn't have a family and he always wore a cabbage leaf on his head. At the end of the film, when the credits rolled, the boy with the cabbage leaf on his head was running down a road.
Obviously I wouldn't be asking information about such a random movie, but this has been bothering me since I first saw it.