OSAKA -- With the late July emergence of Kenichi Shinoda -- also known as Shinobu Tsukasa -- as Yamaguchi-gumi's sixth don, Japan's largest and most notorious mob syndicate now has a boss with a violent past but a reputation as an organized leader and diplomat with strong connections to rival gangs, especially in Tokyo.

Hyogo Prefectural Police warn that the leadership situation in the mob remains unknown, and that the public should still be vigilant against gangland warfare.

The new don is appealing a prison term for a firearms-related offense, and instability could emerge, depending on the Supreme Court's decision on the case.