Advances in artificial intelligence have come along in leaps and bounds in recent years, prompting police in Fukuoka and Kyoto to look into ways of using the technology to tackle organized crime.

The Fukuoka Prefectural Police in Kyushu face a particularly daunting task, with some of the country's most violent crime syndicates operating in their jurisdiction. These groups are so violent they've even been known to lob hand grenades — dubbed "pineapples" in yakuza slang — at each other.

The Kudo-kai has been particularly virulent in resisting police crackdowns and retaliating against civilians who don't toe the line. They're certainly not above murder. In 1998, gang members reportedly killed the former head of a local fishermen's association after he refused to let Kudo-kai get a cut of the harbor business.