From Renta!:

Shota, a guy born with a silver spoon in his mouth, has one dream : to be the cool, bad guy. Ever since he was a young boy, he has looked up to the strongest, worst delinquent in the area, Soushi. But because of his upbringing, he was never able to even pretend to be like him. Now he is finally in university and will start going out at night in order to become a delinquent himself...or at least he was supposed to. Instead, he ends up working part-time at a bar that belongs to his mom's friend, the strong delinquent Soushi! Soushi is divorced, has no kids and has settled down now when he's nearing 40. He's the complete opposite of the guy Shota looked up to! Shota takes it upon himself to make sure Soushi remembers his true self, and he starts by giving Soushi his body, even though Soushi doesn't seem to show much interest at all. This is a comedic and explosive love story between a middle-aged, retired delinquent and a rich and pure delinquent-admiring university student!