Thus Spoke Kishibe Rohan OVA Booklet (March 2020)
Interview with Shunichi Ishimoto, Character Designer and Chief Animation Director for the Thus Spoke Kishibe Rohan (OVA) series, and Toshiyuki Kato, storyboarder and episode director for JoJo's Bizarre Adventure. Published in a booklet that comes with the Thus Spoke Kishibe Rohan OVA Blu-ray release.
Kato: He did want a number of changes made to certain characters from "The Run", such as Yoma. The initial character designs emphasized their physical builds because the story was about weight training, but he said to make them "even more muscular".
Ishimoto: He said to make them about as buff as they were between Part 1 and Part 3. The bald-headed gym patron in particular was the character that required the most revising. During the design process, Mr. Araki said to make him "about as buff as Dwayne 'The Rock' Johnson", and we thought he was kidding because that would be deviating a bit from the original work, but it turns out he was serious (laughs).