Dr. Shimizu is the director at Bar-Med Pharmaceuticals. His estranged son is Tim Shimizu.
During the events of Airwolf: Season 4 Episode 12 X-Virus played by Wong Gerald Shuck
Dr. Shimizu looks at a framed photo of himself and Professor Barton Saunders during the reopening ceremony for Bar-Med Pharmaceuticals. Barton goes to Dr. Shimizu's home and Dr. Shimizu recognizes him and orders him to do the honorable thing and Barton shoots Dr. Shimizu in the neck with a dart and kills him.