Chōjirō Tokumatsu, also known by his former alias of Enjoy Chojiro, is a supporting character who appears during the Synchro Dimension arc. He is introduced as the self-proclaimed boss of the Facility, a vast prison complex located in the lower levels of the City. Unlike typical inmates, Tokumatsu holds a position of unusual authority within the prison, wielding more influence than even the guards themselves.

Before his incarceration, Tokumatsu was a beloved and popular duelist in the Commons, known as Enjoy Chojiro. His dueling style was built on creating a spectacle and bringing happiness to others, particularly children, whom he often taught and entertained. This philosophy of dueling for joy and smiles strongly mirrored the tenets of Entertainment Dueling practiced by Yuya Sakaki. Tokumatsu harbored a deep desire to challenge the oppressive class system of the City and rise from the Commons to the Tops, not for personal glory, but to change the system from within.

However, his ambition was shattered when he attempted to climb the ranks. He discovered that his opponents in the Tops would use their immense wealth to acquire rare and powerful cards, crushing him not through skill but through economic advantage. After a humiliating public defeat, where the crowd that once cheered for him mocked him, a desperate Tokumatsu resorted to cheating in a subsequent duel in an attempt to win by any means necessary. He was caught and subsequently imprisoned in the Facility, where his joyful demeanor curdled into a bitter and cynical outlook.

When Yuya Sakaki and his fellow Lancers are captured and sent to the Facility, Tokumatsu acts as an initial antagonist. He forces Yuya into a duel, using a unique deck of cards known as Cardians, which are based on traditional Japanese Hanafuda playing cards. His strategy revolves around his signature trap card, No Cheaters Allowed, which reflects his own past disgrace by punishing any dishonest action. Throughout the duel, he mocks Yuya for his idealistic and entertainment-focused dueling, projecting his own crushed dreams onto the younger duelist.

The duel with Yuya serves as the catalyst for Tokumatsu’s redemption. As the duel progresses and other inmates begin to watch and cheer, Yuya’s unwavering belief in making people smile rekindles Tokumatsu's own lost passion. Upon his defeat, he abandons his cynical persona and returns to his original role as Enjoy Chojiro, becoming a loyal friend and ally to Yuya and his group. His primary motivation shifts from preserving his pride as the prison boss to supporting the Lancers' cause and rediscovering the joy of dueling that he had lost.

Following this defeat, Tokumatsu plays a key role during the chaos of the Friendship Cup and the subsequent invasion of the City by the Fusion Dimension. Using his authority over the prison, he leads a rebellion of the inmates against the corrupt forces of the Executive Council, helping to liberate the Facility and turn it into a stronghold for the Commons. His character development is a clear arc from fallen hero to bitter jailhouse tyrant and finally to a redeemed ally who fights alongside his former enemies to change his world for the better.

Tokumatsu's most notable ability is his mastery of Cardian monsters, a unique archetype that relies on drawing and managing specific sequences of cards, emulating the rules of the Hanafuda card game. His dueling style is methodical and built on restrictive combos, a direct contrast to the fluid and action-oriented Entertainment Dueling of Yuya. His ace monster and primary strategy revolve around summoning powerful synchro monsters like Cardian - Ameshikou. His personality and reputation among the prisoners are such that he commands a great deal of respect and fear, making his reformation a pivotal moment that rallies the entire Facility to the side of the protagonists.