I remember watching a Japanese anime movie on [adult swim] years ago about a group of children wandering around a city that resembles Tokyo, with lion statues and torii. I've looked through this list but none of the movies listed match what I remember. For a long time, I thought the name of the movie was Battle Royale, but I later learned this was false. I think the reason I believed the name was Battle Royale was because it seemed like a version of The Warriors with children.
I believe that I saw this movie sometime between 2005 and 2008. Other than the possible plot of the children being sent out into an empty city, I don't remember much more of the plot. My most vivid memory of the movie is two children under a lion statue with a torii in the background.
Most of the movie was red. It seemed like most of the buildings and objects except for the children were red.