Esteemed scientist and archeologist Professor Asuka who became a failed attempt at creating the first Devilman in the series. In most incarnations he is the father of Ryo Asuka.
- Professor Asuka (Manga): A archeologist that supposedly discovered the Demon Mask and killed himself after fusing with a Demon.
- Professor Asuka (OVA): Following the same story as the manga, Asuka found the mask and commited suicide after being posessed.
- Professor Asuka (Grimoire): This version had no relation to Ryo/Satan, mostly due to them not really being a centrepiece of the story. He was a scientist that was acidently killed by Tsubasa Rainuma.
- Professor Asuka (Film): This version discoverd demon kind during an expedition, and was forced to record his last moments in a video for his son Ryo to see.