The Unlikely Hero

Set up a character that at first seems to be the antithesis of a hero. If you have a major idea to get across to the audience but you don't want to sound preachy by giving it to the your character (remember the ultimate focus is on this character), why not use your unlikely hero to convey your idea.

Examples:

A coward who does something heroic (most obvious)
A drug dealer who displays an honest action
A businessman who displays a sensitive side.