The One Piece manga and anime series features an extensive cast of characters created by Eiichirō Oda. The series takes place in the fictional world of One Piece where vast numbers of pirates try to reach the end of the Grand Line, the intersection of the world's surface, in hopes of finding the legendary treasure One Piece.

The main character of the series is Monkey D. Luffy, a 17-year-old boy who wishes to become King of the Pirates by obtaining the titular treasure One Piece. During the series, he recruits a number of crewmates, which include Roronoa Zoro the swordsman, Nami the navigator, Usopp the marksman, Sanji the cook, Tony Tony Chopper the doctor, Nico Robin the archaeologist, Franky the shipwright and Brook the musician. Over the course of the series they interact with several characters in the world, encountering both allies and antagonists.

Source: Wikipedia