Gennosuke Yumi

A former colleague of Kouji's grandfather Juzo, Professor Yumi is the current head of the Photon Power Research Laboratory. He is the father of Sayaka Yumi and also built her robot, Aphrodai A.

In Shin Mazinger Shougeki! Z-Hen, his name was changed to Yannosuke, despite all the previous Mazinger series referring to him at Gennosuke.