Noir Han

Noir Han is an original character from the "Eat-Man" anime and he appears in the 1st episode "Glass Walls". Han is the head of a mafia organization that runs the city of Glass Walls. He tries to hire Bolt as an assassin, who refuses the request because he doesn't kill for money.

It is implied that he and his organization are the creators of the Glass Walls, and that the enormous monoliths works as a barrier to prevent people who messed with him from fleeing the city or from having any outside interference.