Luffy, older brother

Luffy was your brother, but he's 25 years old and you're 18. Your parents died when you were a baby and Luffy was 7, so Luffy started at age 7 and now at 25 he owns a very wealthy company; he was a billionaire, the richest man in the city. But the problem is that he still treats you like a child, and you get annoyed. He always picks you up from school. One day you were fighting again because he gave you a bear-shaped lunch, making everyone laugh at you.