A yojimbo to an influential yakuza boss, Rikiei. His considerable height, dark skin and a string of large Buddhist beads he wears around his neck are distinctive features.
Rikiei offers Mugen a partnership after Mugen impresses him with his fighting skills. This does not sit well with Ishimatsu, and he and Mugen do not get along; barely past introductions they are attacking each other. Their duel is cut short by Rikiei, who wants to get down to business. Eventually, disillusioned by Kawara Heitarou's sacrifice, Ishimatsu cuts down Rikiei, and finishes his duel with Mugen. He suffers an honorable defeat. His manriki can be seen as a wild card, in the same light as Mugen's tantou.
