Genjo Kakouton is a prominent fighter from Kyoshou Academy and serves as the trusted right-hand man and closest friend of the academy's leader, Moutoku Sousou. He is a high school student in his second year, studying civil engineering. Kakouton is the fictional counterpart of the historical Three Kingdoms general Xiahou Dun.

Kakouton has a distinctive appearance, characterized by his dark skin, long black hair often tied back, a goatee beard, and a tall, fit build. His typical attire includes sandals, a beanie, and a green coat. Following a significant injury during an assassination attempt on Sousou, he loses his left eye and subsequently wears an eyepatch with a pirate motif.

His personality is defined by a deep-seated obsession with the fundamentals, or basics, of street fighting, leading him to constantly shout about them during combat. This earned him the nickname Basics Ton-chan from fellow fighter Hakufu Sonsaku. He holds a strong belief that contemporary fighters have lost their way by abandoning these core principles. An eccentric yet honorable individual, Kakouton feels a profound responsibility towards the physical spaces where battles occur. He views the streets as sacred grounds for fighters and dedicates himself to repairing any damage caused during his fights, a habit that aligns with his civil engineering studies.

Kakouton's primary motivation is unwavering loyalty to Sousou and the protection of Kyoshou Academy. This sense of duty is tested repeatedly as he navigates the political and violent landscape of the warring schools. Among his key relationships, his bond with Sousou and their mutual friend Houkou Kakuka is the most significant, as they were ordinary individuals who rose to power together. He is also the subject of a rumor, stemming from persistent flirting by Hakufu's mother, Goei, that he has a preference for mature women, a claim he vehemently denies. Despite this rumor, he harbors a genuine crush on Hakufu Sonsaku.

In the story, Kakouton initially acts as a formidable frontline fighter for Kyoshou. During the Great Toushi Tournament, he defeats Hakufu by targeting her legs, a strategy advised by Goei. He is ultimately defeated in the semi-finals by Shimei Ryomou. A turning point occurs when an assassin gouges out his left eye while protecting Sousou, an event that triggers the awakening of Sousou's destructive dragon spirit. Following the death of his friend Kakuka, Kakouton is ordered to launch a sneak attack on Nanyo Academy; he reluctantly agrees but insists on carrying it out in a way that honors his personal principles.

His development is marked by growing concern over Sousou's increasingly violent and bloodthirsty behavior caused by the dragon within. This leads to his most courageous act: defying Sousou's orders and releasing a captive Unchou Kanu in an attempt to save his friend from the demon king possessing him. This act of loyalty results in a brutal confrontation where Sousou, fully possessed, crushes Kakouton's hand, leaving it permanently disfigured. He is presumed dead but survives, though with amnesia. In the subsequent series, Great Guardians, he journeys with a similarly amnesiac Ryofu, eventually recovering his memories after being reminded of his precious repair kit by Hakufu. Following these traumatic events and his hand injury, his role transitions from an active combatant to a more strategic advisor and second-in-command for Kyoshou.

Regarding his fighting abilities, Kakouton is officially ranked as a C-Class fighter. However, his skill and tenacity allow him to hold his own against much higher-ranked opponents, including A-Rank and Special A-Rank fighters, earning him respect even from rival schools. His fighting technique is almost entirely based on hand-to-hand combat and close-range melee, focusing on the basics he so reveres rather than flashy or complex maneuvers.