Takeo Shigeda
Takeo Shigeda (重田 武雄) was the Oyabun (syndicate head) of the Shigeda-gumi. He's rather behind-the-scenes compared to most Yakuza leaders, choosing to leave many day-to-day operations to the Wakagashira (Right-hand-man, Second-in-command) or the Saiko-Komon (Chief-of-staff). However, in 2072 he was assassinated, and his wakagashira, Sato Kanaga took over and formed the Kanaga-gumi.
Rumor has it that Shigeda was assassinated due to his liberal non-conservative stance and policies in contrast to the Shotozumi-gumi, only exacerbated by the fact that Kanaga is much more conservative and this had been a point of contention in the past. Since there wasn't a strong internal investigation, there's good circumstantial evidence that this was an inside job.
> Shigeda and his son got done in by one of his own bodyguards; how does that not reek of an inside job? -- Danger Sensei >> Word has it that the bodyguard also disappeared afterwards. Coincidence? I think not. -- Kazuo