Information:
This is a group of male and female seiyuu (voice actors and actresses who voice roles for anime) who all voice various characters for the popular One Piece series (Luffy, Zoro, Nami, Usopp, and Sanji respectively). Each of these seiyuu have several noteable roles.

Tanaka - Krillin (Dragon Ball, Dragon Ball Z, Dragon Ball GT), Koenma (Yu Yu Hakusho), Fujinami Ryuunosuke (Urusei Yatsura), Kanna Kirishima (Sakura Taisen). Nakai - Etou Kouzou (Nodame Cantabile), Mugen (Samurai Champloo), Jan Valentine (Hellsing). Okamura - Belldandy (The Adventures of Mini-Goddess), Imonoyama Nokoru (CLAMP School Detectives), Koizumi Risa (Lovely Complex), Fio Piccolo (Porco Rosso), Fujii Kasumi (Sakura Taisen). Yamaguchi - Saotome Ranma (Ranma 1/2), Tonbo (Kiki's Delivery Service), Inu Yasha (Inu Yasha), L (Death Note). Hirata - Sha Gojyo (Saiyuki series), Narrator for the Digimon series.