Sabo

He was born into a noble family but decided to run away and live in the Gray Terminal, eventually setting out to sea on his own. 12 years before the present storyline, he was a childhood friend of Ace, and eventually Luffy as well, to the point where the three considered themselves to be "brothers." Along with Ace and Luffy, Sabo's dream was to become a pirate so that he could set sail and achieve freedom, and made plans with his brothers to set sail at age 17.