Koby[9] is a Marine Captain[3] who trained together with Helmeppo under Vice Admiral Garp's supervision. He is currently a member of the Marine special forces unit SWORD.[10] He was formerly an involuntary pirate ship caretaker for the Alvida Pirates until he was liberated by Luffy, and he was the first person Luffy befriended on his travels. He is Luffy's ally during the Romance Dawn Arc. He and Helmeppo are also the central characters from Diary of Koby-Meppo Cover Page Serial.