It is a movie I saw in 2008, but I don’t really know the year of the movie (I downloaded it via torrent because I saw the recommendation in a forum post), my best guess is that the movie is from anytime between 2000 and 2008. I’m pretty sure it is Japanese (if not, it is Asian for sure).
Whatever search I make results in “icchi the killer”, but it isn’t that movie.
What I most remember it is a scene where there is a large room with a lot of chickens covered by a white sheet and the main character (a psycho leader of a gang) begin shouting and stepping on the sheet killing the chickens below the sheet.
Could it be “Suicide Club”? There’s a scene in a bowling alley similar to your description, but with various unseen animals in sacks, not chickens under a sheet. This the scene I’m thinking of: