|Japanese Name||Shinichi Kutsukake (沓掛真)|
|Age|| 35 (Under the Knife and Second Opinion)|
38 (Under the Knife 2)
|Family|| Sidney Kasal (younger brother)|
Cybil Myers (spouse)
|Friends|| Derek Stiles|
Dr. Greg Kasal's surgical skill, coolness under pressure, and reliability earned him a position as Hope Hospital's Senior Surgeon. He's the manager of the office for all intents and purposes, and is a kind person. However, he takes his job very seriously, and expects others to do the same. He is the first to be infected with the fourth strain of GUILT, Tetarti. He is the identical twin brother to Sidney Kasal. He appears in Under the Knife, Second Opinion and Under the Knife 2. He has brown hair and hazel eyes. He wears a lab coat over a beige dress shirt and wears a green tie with yellow and black stripes. Some fans know him for his famous 'finger on chin pose'. In Under the Knife 2 his uniform is a brown suit and he is the director of Hope Hospital.
In Under the Knife 2, Greg is married to Cybil Myers and they have a baby daughter named Kari.