Hachiman is a samurai warrior and master swordsman from Ancient Japan. Summoned to Third Earth by Mumm-Ra, he was tricked into fighting Lion-O, but thanks to his code of Bushido, he became an ally to the Thundercats and the Warrior Maidens of the Tree Top Kingdom. He wields a sword known as “The Thunder-Cutter,” a katana-blade that, with his skill, can cut through solid stone. Hachiman has saved the lives of various Thundercats on multiple occasions. Hachiman maintains a friendship with Lion-O after they first join forces. During the race to rescue Pumyra, Ben-Gali, and Lynx-O, he is again briefly tricked into attacking the Thundercats—specifically Lion-O—by Mumm-Ra. However, he eventually realizes that he has again been deceived and sides with the Thundercats once more. In his final appearance, Hachiman is shown to be living on his own planet which resembles ancient Japan. He is a determined fighter, and on occasion be too brash for his own good. Hachiman will sometimes rush into battle unprepared to protect his friends and loved ones or to defend his own honor. He would rather sacrifice his own life than let an ally down.