Does anyone know this manga?

So a while back I read a manga that I'm not sure I liked and want to give it another shot.

Its about two guys who use to be friends. One of them is a business man( forget what time of business but wanna say its illegal). The friend of the businessman becomes his "steed" for an underground match in which if you lose your humiliated. The friend does this because he feels he owes his friend. The friend does it as a payback because of something that happened in their childhood. Tho it turns out that the friend ( the one that was the "steed" was lied to and he tried to get help and was injured in the process. The business friend finds out the truth and feels bad and tries to get the friend out of the mess that he put him in.

I dont recall anything else other than that. Anyone know it? Thanks