Iron Michael was the heavyweight boxing champion. In the anime, his name was changed to Ian McGregor (イアン･マクレガー) and he was renamed to Olam McGregor in the English version of the anime.

He respects strong rivals to the point of taking off his gloves to fight them, such as he did in his battle against Chiharu Shiba. He loves his hometown of Brooklyn. He does not show contempt for challengers who fight using weapons or fighting three at a time. He loves boxing and idolizes the late God of Boxing John L. Sullivan (renamed in the anime to Johnny L. Donovan). It can be seen also in the scene where he were happy, telling Baki that in three months he was going to box again. He also believes that weight is the most important thing in an exchange of blows. The reason why he went to prison is unknown.

(Source: Baki Wiki)