This is what happens when you 1) institutionalise crime syndicates, and 2) maintain a massive territorial presence. Yakuza keep the peace at night, police keep the peace during the day; and there's a police booth (and a Yakuza joint) every few blocks. That means a 24/7 guarantee that, if you fuck with anything, you'll meet speedy (and pretty painful) "justice" before you can say "I want a phone call". It's not pretty but it mostly works. At that point, the rest of the system is basically a formality. The dark side of this is obviously that, if you're a "false positive" (i.e. an innocent caught up in stuff), you're screwed, because the police won't allow your case to ruin their "perfect score" - so guilty you must be.