The headmaster of Otokojuku (男塾, Man's Private School?) and a former Navy Major General. He is a bull-headed kendo master teaching troubled youths to be warriors. A child prodigy who entered Tokyo University at a very young age with only a week's study. He fought bravely in World War II as an imperial soldier. This character is modeled after the Imperial Japanese Navy admiral Togo Heihachiro (東郷平八郎; The city of Edajima (江田島) was the site of the former Japanese Imperial Naval Academy; see ja:海軍兵学校). Whenever he's about to deliver the coup de grâce to his enemy, he shouts his famous one-liner: "I AM THE PRINCIPAL OF OTOKOJUKU, EDAJIMA HEIHACHI!!!" (わしが男塾塾長江田島平八である！！, Washi ga Otokojuku Jukuchō Edajima Heihachi de aru!!?). Any inquiry in regard to many of eccentric Otokojyuku rule or his decision is also answered by this one liner.

The character was famously cosplayed by Lee Teng-hui, former President of the Republic of China, Taiwan.

Heihachi was most likely the main inspiration for Mishima Heihachi, one of the main villains of the cult Tekken fighting franchise, with whom Edajima not only shares an almost identical appearance, personality, and role in the plot, but even have one voice actor.

(Source: Wikipedia)