Read Shinjuku Swan manga
Shiratori Tatsuhiko was a bum wandering the streets with no money to his name when he meets Mako. He works as a scout for an agency called Burst that recruits girls on the streets for adult entertainment in the Shinjuku area of Tokyo. Tatsuhiko quickly learns the techniques of scouting and is even more attracted to how much money he can make. But with how the industry is maintained, Tatsuhiko has to deal with the lying, deception, violence, greed and even the yakuza. He wants to keep the morals that he has, but it gets progressively harder and harder as he gets deeper into the other side of society.