| NAC |
NAC is a character exclusive to the manga series.
This character is loosely based on Satoshi Nakamura (中村聡, Nakamura Satoshi), a Japanese card game player who became one of the top Magic: The Gathering players in Asia. He was involved in the making of Duel Masters, assisting Dai Matsumoto (the manga author's nickname) as a technical advisor (the manga's plot is based around Magic: The Gathering).
He has appeared in the manga both as NAC and as a more realistic cameo of himself known as "Nakamura-san". According to one of Dai Matsumoto's omake sections in the manga, NAC was also involved in the development of the Duel Masters card game.