Hachizou Onizuka, age 55, is a rookie class police instructor at the Metropolitan Police Academy and an old friend of Sato's father. He has trouble dealing with problem students in his own classroom. He had instructed Kogoro, Furuya, Date, Matsuda, Hagiwara, and Hiromitsu. He appears in Wild Police Story and its anime version.
(Source: detectiveconanworld)