A boy named Monkey D. Luffy, inspired by his childhood hero "Red-Haired" Shanks, sets out on a journey to find One Piece, the legendary treasure of the King of the Pirates, Gol D. Roger. To accomplish this, he must reach the end of the most deadly and dangerous ocean: The Grand Line. Luffy captains the Straw Hat Pirates first through the sea of East Blue and then through the Grand Line. He follows the path of the deceased King of the Pirates, Gol D. Roger, from island to island on his way to the great treasure One Piece. On his way his crew grows to have a swordsman – "Pirate Hunter" Zoro, a navigator – "Cat Thief" Nami, The sharpshooter – "Sogeking" Usopp, a cook – "Black Leg" Sanji, a doctor – "Cotton Candy Lover" Tony Tony Chopper, an archaeologist – "Demon Child" Nico Robin, a shipwright – "Cyborg" Franky,and a musician – "Dead Bones" Brook. During the course of the story, the crew contends with other pirate crews, the royal Shichibukai (7 Warlords of the Sea) and the Marines. The latter are the subordinates of the corrupt World Government, who apparently seek justice by ending the Golden Age of Pirates. Many background story elements involve the delicate balance of power between the World Government and the world's most powerful pirate crews, especially the Four Emperors, the four most powerful pirates in the world.