Volume 3: Something You Can't Lie

After Luefy has defeated Buggy, he got Nami to become his navigator. In order to go to Grand Line, Luefy and his team need a better ship and other neccesary supplies. They stop at a small village where they meet Usop, the Liar of the village. Usop told them that they might get a good ship from the richest girl in the village, Kaya. However, when Luefy went to see Kaya, Kurahadol, Kaya's caretaker, drove them away from there.
Luefy and Usop have a talk and Luefy remembers that Usop is a son of one of Shank's crew, Yasop. While Luefy and Usop are talking, Luefy sees Kurahadol talking with a mystery man. They learn that Kurahadol used to be Captain Kuro, the leader of some very cold-blooded pirates. Kurahadol was planning to murder Kaya and inherit all of her treasure. Usop tries to warn everyone in the village, but no one believes him because he was always a liar! So, Usop decides to fight Kurahadol with the help of Luefy and his team.