Troublemaker – Weezer
All the Usamis are difficult people – it's practically how they make their living. They're all intelligent, stubborn and well and truly spoilt. Most have an edge of almost malicious cunning, and Akihiko is no different.
He knows what he wants, and has a vague sense of what he requires, and it's a simple case of getting it. He can argue and manipulate and bully, stick his ground and defy the worst opposition with the best of them. He's probably better than most of his family at it, in fact.
What sets him apart is his simple lack of respect for familial authority. For any authority. There's nothing Akihiko seems to think he needs to do for the Usamis. There's no teamwork, no connection. While his relatives are fine working together for their own good and financial gain, Akihiko would rather go his own way and do his own thing and be happy.