Doitsu is a character version of the card, "Doitsu". Doitsu appears in the video game, Yu-Gi-Oh! World Championship 2007. He appears as a Level Three Theme Duelist and he challenges the player to equip 5 or more Union Monsters during a Duel. By beating him, the player gets closer to unlocking Level Four Theme Duelists and a new Booster Pack.