Dr. Ishinami is Shioso's father and the one who created the bioroids in the "Hero Killer" manga. He was murdered in cold blood 5 years before the story takes place and only appears in Shioso's flashbacks. Most of his lines are after he's been attacked and is dying, trying to pass on what information he can to his son before dying. 

I picture him sounding very educated and considerate. The biggest thing for him though is being able to convincingly act out the dying scenes.