Jubei Yamada (山田十平衛) was a close friend to Mai Shiranui's grandfather, Hanzo Shiranui. He is master in the arts of Ninjitsu and mainly responsible for Mai's training after her grandfather had died.
 Story (in the Fatal Fury Saga)
In Fatal Fury 2, Jubei has the first dash-and-throw move in fighting game history.
In the past, Jubei Yamada was such a fierce Judo warrior, that his prowess and skill that he released in his matches earned him the nickname of "The Demon". Now he is a giddy old man who passes his time eating cookies and taking care of his dojo, where he looks over the progress of his many students, Jubei has resorted to a more peaceful life. Having chosen to live away from the ways of fighting, Jubei rested in his dojo, with not too much effort spent. He spends his time with his old friend and rival Hanzo Shiranui, a Ninjitsu master and well trained in the ways of Koppo-ken.
Hanzo had been training his granddaughter Mai in the Shiranui Ninjitsu style, but when he was approached by a young American boy called Andy Bogard who wanted to learn the Koppo-ken art, Hanzo left Mai to complete her training with Jubei. Jubei realized that Andy had a lot of potential to become a superb fighter.
Even though his golden age has long been gone, Jubei refuses to sit back in a bed and wait for his death. Jubei likes to be where the action is, and always tries to live his remaining days as a youngster. Revived by the passion of other young fighters as Andy and Mai, Jubei takes a cue, and always takes to the fighting arena every now and then.
He has not appeared as a playable character since Fatal Fury Special, officially based on the fact that he decided that he is too old for fighting and is better off staying at his dojo.