* Filipino Name Master Geremaiah
* Seiyu: Kyouda Hisako
* Seiyu (Young): Megumi Hayashibara
* Voice actor: Linda Young
Genkai, aging master of the Reidoha (or Spirit Wave) fighting technique, wishes to pass her knowledge to one worthy pupil before she dies. Yusuke is chosen to be that pupil, and he soon discovers Genkai's training to be the most difficult ordeal of his life. Despite her advanced years, Genkai constantly amazes Yusuke with her ability to perform superhuman feats of strength and agility. Her wit is as finely honed as her technique, and she possesses the wisdom that comes from a life rich with experience. Impossible to intimidate, she stares unflinchingly into the face of danger, ready to meet even the most daunting of challenges while remaining sarcastic. She is called Master Geremaiah at Philippine dub.