Kenji Mitsusada, nicknamed "Koutei" (Emperor), is a high school student beginning his third year at Tokyo Metropolitan Harumi High School and later attending Jigen High in a spin-off. His surname signifies "Light" and "Determination." He commands Team Caesar, featuring Yuri Usui and her younger brother Gai Usui, having previously held the national champion title before losing it to Ren Suzugamori's Team Asteroid. He sports short blonde hair and silver eyes, typically wearing white pants, dark shoes, and a long crimson coat with black lining. A pendant gifted by Yuri adorns his neck, later replaced by a headband inherited from Gouki Daimonji. His personality blends carefree and careless traits; he enjoys cardfighting without fixating on victory or defeat and maintains punctuality despite often running late. Generally friendly and courteous, he treats rivals like Team Q4 respectfully and offers encouragement. This demeanor shifts dramatically during his "Reversed" state, where he adopts tyrannical methods to enforce his will, though defeat restores his original self. His backstory reveals an early passion for Roman history, especially Gaius Julius Caesar, inspiring his nickname and team name. As a rookie cardfighter, he frequented Gai and Yuri's card shop, losing repeatedly but rapidly improving until Yuri invited him to join their team. He eventually surpassed both siblings, becoming team leader and inheriting Yuri's pendant. In the Super Dimension Robo Daiyusha spinoff, his father leads the Earth Defense Organization "Caesar," and Kenji, depicted as a robot enthusiast, discovers and recruits the Dimensional Robo Daiyusha after it rescues him from Shadow Paladins. During the first national tournament, humiliation against Ren Suzugamori leads him to seek collaboration with Team Q4 for mutual improvement. In the next national, he loses to Aichi Sendou after failing to counter Alfred Early. He later participates in the VF Circuit during the Asia Circuit chapter. In Singapore, Team Caesar performs strongly but loses to Team S.I.T. Genius. In Seoul, Kenji achieves a rematch victory against Ren by executing a superior crossride into Ultimate Dimensional Robo, Great Daiyusha under the "Stand 3" rule, though his team loses overall. Post-circuit, he retires from competition to study at the Singapore Institute of Technology. Returning in Season 3, he cardfights Kai Toshiki at the airport and loses, subsequently being Reversed by Kai. As a Reversed entity, he defeats Christopher Lo and Yuri but is restored after losing to Leon Soryu, who exploits the Limit Break of Dark Dimensional Robo, "Яeverse" Daiyusha. In Season 4, he travels globally but loses memories of Team Q4, leaving him unfamiliar with members like Misaki and Kamui. He encounters Quatre Knights members Raul Cera and Ratie Curti, unaware of their agenda; Ratie forces him into a cardfight and defeats him using Shadow Paladin witches. After failing to locate Ratie and Misaki, he departs with Yuri and Gai. By Season 5, he appears in a film titled "The Chronicles of the Dimension Police" and visits Card Capital #2, where Chrono requests his autograph. In Season 6, he is implied to wield Great Daikaiser. As a cardfighter, he exclusively uses Dimension Police decks. His initial build centers on Enigman Flow and Enigman Storm, leveraging grade security and hand advantage, with Commander Laurel enabling a finishing move by resting four units to restand the vanguard. Later, he adopts a "Super Combination" deck featuring Dimensional Robo units like Goyusha, combining them into Great Daiyusha, emphasizing a powerful vanguard line through soul-based skills.