Koheiji Nakata is a student at Teiken High School and the self-appointed leader of the Koheiji Corps, a small group of followers he gathers around himself. He comes from a wealthy family and has a younger brother, Sanpeita, who is studious and earnest, forming a strong contrast to Koheiji's loud and comedic nature. Koheiji is defined by his oversized confidence and relentless posturing as the school's top delinquent, though in reality he is clumsy, prone to bluster, and far from the strongest fighter in the series. His personality is a mix of childish pride, genuine loyalty, and a desperate need for recognition. He frequently proclaims himself the rival of the main protagonist Taison Maeda, but his challenges are always met with indifference or easy defeat, which he never seems to fully learn from. Despite this, Koheiji shows a surprising depth of character through his motivations. He craves respect and fears being seen as irrelevant, and this desire drives most of his actions. He also possesses a strong sense of family duty, most notably when he confronts his own past failure in baseball to help his brother Sanpeita join the school's baseball team, an episode that reveals his capacity for selfless love and quiet sacrifice. His role in the story is primarily that of comic relief and a minor ally. He initially acts as an obstacle but quickly transitions into a supporting figure who provides humor, unexpected moments of heart, and occasional moral support during larger conflicts. His key relationships include his two long-suffering followers, Hiroshi Ohno and Hiroyuki Koyama, who are often exasperated by his antics yet remain loyal to him. His relationship with Taison Maeda is one-sidedly competitive, but he eventually comes to respect Taison and stands with him during group battles. His younger brother Sanpeita is the person who brings out his more responsible and caring side. Over the course of the story, Koheiji experiences modest development. He shifts from being purely self-aggrandizing to occasionally acting out of genuine concern for others, especially his brother and his corps. He graduates from Teiken High School and later founds the Corps Preservation Society to keep his legacy alive, showing that his persistent, stubborn spirit does not fade. In terms of notable abilities, Koheiji is not a skilled brawler and loses most of his fights, but he possesses an odd luck or determination that surfaces at key moments. His unexpected boxing victory using a cat punch during a school match against Yokohama Teiken High School is a highlight, demonstrating that under the right circumstances his boldness can produce surprising results. His true strength lies not in combat prowess but in his refusal to stay down, his loyalty to his small group, and the way his earnest, foolish charm earns him a place among the other characters despite his shortcomings.