I know it was about a former gangster who quit being one because his friend went to jail. He works with a bulky middle-aged man whom he admires to be like. There was a scene when a group of kids went to his restaurant and pulled a prank by putting pubic hair in the food. Then the rest is shows a male family member of the guy who went to jail. There's incest in it, I know that. Please help me!!

I'm pretty sure what you are looking for is Endless World.