Bob Makihara is a prominent character known for his physical prowess and distinctive background as a foreign student at Toudou Academy. A young man of South African descent, he stands out in the series due to his appearance, which includes a muscular build and, for much of the story, long dreadlocks. He is a first-year student who arrives at the academy with his best friend since elementary school, Souichiro Nagi, with the shared goal of conquering the school through sheer strength.

Bob’s personality is defined by a love for fighting combined with a perceptive nature that often sets him apart from his more impulsive partner. While he enjoys combat, he possesses a greater awareness of his surroundings and quickly senses that Toudou Academy is home to fighters far beyond anything they have encountered before, recognizing the latent power in individuals like Masataka Takayanagi and Maya Natsume. Despite his tough exterior, he has a strong sense of loyalty and a caring side, particularly when it comes to protecting his girlfriend, Chiaki Konoike, for whom he harbors deep affection. He is disciplined in his training and shows a remarkable degree of fidelity, famously rejecting multiple offers from the powerful Mitsuomi Takayanagi to leave the Juken club and train under him, choosing instead to remain loyal to his new allies.

The character’s primary motivation stems from a desire for strength and revenge. After he and Souichiro are brutally defeated by Tsutomu Ryuuzaki of the Enforcement Group—an incident that also results in Chiaki being assaulted—the pair join the Juken club specifically to become more powerful and settle the score. Within the club, Bob serves as a key member and a physical powerhouse. His role in the story is largely defined by his journey to unlock his true potential, which frequently puts him at odds with his own self-doubt regarding the effectiveness of Maya Natsume's rigorous physical training regimen.

His relationships are central to his character arc. His partnership with Souichiro Nagi is the most significant, as they have been inseparable since childhood, calling themselves the "Knuckle Bombs". He also develops a deep respect for Masataka Takayanagi after being easily defeated by him, recognizing his skill and forming a bond as comrades in the Juken club. His relationship with Chiaki serves as an anchor, as her concerns and love often influence his decisions, such as when she convinces him to stay away from Mitsuomi’s influence.

Bob undergoes notable development, primarily in his fighting abilities. Initially relying on raw power and his base martial art, he later awakens a unique skill referred to as "Rhythm." During a desperate fight against the assassin Madoka Mawari, Bob discovers he can sense vibrations through the ground, allowing his body to instinctively dodge attacks and move to a "beat" that he feels in the earth. This ability aligns with Mitsuomi’s observation that dance and martial arts are historically linked, and that Bob’s talent for the former makes him a potentially great fighter. After this battle, his signature dreadlocks are damaged, forcing him to cut them off and adopt a new look with a buzz cut.

His notable abilities center on his immense physical strength, which Maya Natsume notes is the greatest in the entire group, even if his technique initially lags behind. His primary fighting style is Capoeira, an Afro-Brazilian martial art that incorporates dance-like movements, acrobatics, and rhythm, which suits his body type and eventually leads to the development of his vibrational sense. In later events, Bob continues to grow, eventually marrying Chiaki and starting a family with her, showing a future where he balances his life as a martial artist with his personal commitments.