Is it a bit like this? [ame="http://www.youtube.com/watch?v=ZBMirqjyA0U"]the mystery of chess boxing 1979 kung fu movie - ninja checkmate - YouTube[/ame]
By the name it sounds like Jiu Jitsu mixed with Boxing. A bit like Kick-Jitsu (which really is just a variant of Japanese Kickboxing).
Definition of a Jit from the urban dictionary The term jit is originally prison slang. It just means somebody younger than you. However, it is most often used to refer to young thugs/wannabe thugs or other punky kids. For instance, you wouldn't call your 10-year-old cousin a jit. If you leave your car there, those jits will steal your spinners. So is it boxing young thugs so they don't steal your spinners?
Apparently he's a black belt in BKJJ a popular ju jitsu club around here as well as a black sash in san shou.