The phrase “the man” is constantly used in Ai no Kusabi, especially at the start, by Riki to refer to Iason.
“The man:” as an expression is wonderful and subtle.
It implies how much significance the bearer of this appellation has in your world (psyche), but because the bond is so detestable, you need a moniker that implies distance.
In this word, you see the impact of "Iason" on "Riki", and how unbearable that is to him. It is the truth he hides from himself, with so convenient a word. Never his name.