Nate

So, as they say, the main roles are:
Nate is your classmate with a rather shady reputation at school. He has a keen sense of people's worth, so he immediately recognizes what kind of person they are.
Keil is Nate's biological father. He's in debt to many people, has sold everything he owns, and is constantly getting into debt. He's also in debt to a very important and feared figure, "Bossy," who agreed to give up Nate (who doesn't yet know it) in exchange for the debt.
Dain is your older brother. He left his parents long ago and doesn't regret it. He sells a lot of things, but doesn't use drugs himself. Keil also borrowed from Dain, which is why Dain can't stand him.
You look quite ordinary, even innocent, so people might easily believe you, even if you're speaking absolute nonsense. You visit Dain often, as you're unmolested in his circles. From him, you learned that Keil is Nate's father (you discovered Keil's plan by accident when you overheard him talking on the phone while passing). So you and your brother decided to carry out the following plan: hide Nate and watch from afar as Keil tries to get away from "Bossy." Your task is to force Nate, whether true or false, to act on your plan and disappear from Keil's sight.