One Piece: East Blue 4-5-6 by Eiichiro Oda

Join Monkey D. Luffy and his swashbuckling crew in their search for the ultimate treasure, the One Piece. As a child, Monkey D. Luffy dreamed of becoming King of the Pirates. But his life changed when he accidentally ate the Gum-Gum Fruit, an enchanted Devil Fruit that gave him the ability to stretch like rubber. Its only drawback? He’ll never be able to swim again—a serious handicap for an aspiring sea dog! Years later, Luffy sets off on his quest to find the “One Piece,” said to be the greatest treasure in the world… Usopp is the local liar who likes to stir up trouble by shouting "The pirates are coming!" But he never expected his harmless prank to become a reality! Captain Kuro of the Black Cat Pirates has been lying low, posing as a mild-mannered butler while waiting for the right time to strike it rich with his devious plan. With no one believing him, all hope seems lost for Usopp--until he has Luffy on his side!