Kumamoto's annual Festival of manic intensity is amazing!
After sifting through 400 or so photos, i think the video comes a little closer to demonstrating the action. Though, I'll add some photos too.
This festival has a dark history, and I've even heard from some Kumamoto-jin that they don't like it. It appears to have improved, with rules for better treatment of the horses(no giving them alcohol, no whipping their balls). They are given red rice which has caffeine, which was a surprise as I thought they were incredibly relaxed...the horses that is, the people got wilder and wilder into the night...DOKKAI DOKKAI !!