Master Mikado is a minor character in The Bouncer.
Master Mikado's Grave
He ran the Mikado Group as a promising leader, even taking in Echidna and Volt to become his own bodyguards. He actually took in the latter as a deal with some gangsters went awry at Edge. Wong was soon chosen being he's a martial arts expert, a little before he took in Sion, until one fateful stormy night when he took in Dauragon as a 15-year-old and giving him a ride to the nearest hospital to save his dying sister, Dominique. Several years later, Wong gave Dauragon the offer of becoming Master's adoptive son, only to excel scholastically while enhancing his body, mind, and soul. He accepted he shall succeed/exceed all challenges to become the leader of the Mikado Group. It wasn't really shown in-game, but it's been hinted that Dauragon expedited Master's death by hiring assassins like Mugetsu and killing Master by his own hands and framing Volt. He was then seen with Wong looking over his grave, with his bodyguard declaring he's Master's new successor!
Although his legacy was in vain since Dauragon assimilated the corporation! Though things were made right again as Volt avenged his death.
The Bouncer tetralogy[]
Master Mikado was only seen in a flashback as Dauragon recollected his sister dying from terminal illness, as well as accepting to follow his legacy, and looking over his grave. Of course, both Volt and Trunks avenged him as the Saiyan helped him defeat the tyrant.