Kenji Harima is a central figure in the second semester of School Rumble, a tall and physically imposing high school student known for his delinquent appearance. He typically wears a black school uniform jacket worn open over a red shirt, black pants, and often has a headband tied around his head. His most recognizable features are the sunglasses he constantly wears and the facial hair he initially grew to hide his identity, which has earned him the nickname Hige, meaning beard, from some classmates. His past as a juvenile delinquent has left him with a large scar running from his right shoulder to his left hip, a permanent reminder of the fateful encounter that changed his life.

Beneath his intimidating exterior, Harima possesses a surprisingly complicated personality. While he is quick to anger, prone to fighting anyone who provokes him, and has a reputation as the terror of the school, he is at heart a deeply sincere and good-natured individual who would go to great lengths for his friends. He is, however, not very bright academically, receiving very poor grades in most subjects. This is contrasted by his natural talent and passion for art and sports. A significant part of his character is his surprising nerdiness and deep-seated self-consciousness, which often leads him to make loud, dramatic declarations that are comically underscored by an explosion or some other chaotic event in the background. Much of his antisocial behavior and the numerous misunderstandings he finds himself in stem from an inability to clearly express his feelings and a sheer, often unfortunate, idiocy.

The driving force behind nearly all of Harima’s actions is his obsessive and unrequited love for his classmate, Tenma Tsukamoto. This love began when he defended her from an attacker, an act that earned him his scar. As she was unconscious, he carried her to his home to recover, but she awoke with a misunderstanding, believing he had ill intentions, and fled from him. In that moment, Harima realized he had fallen in love. Determined to be near her without scaring her away when they entered high school, he grew his hair and beard and started wearing sunglasses to disguise himself. His entire goal for attending school becomes to find the right moment to confess his feelings to her. His elaborate schemes to win her heart almost always backfire spectacularly due to his own clumsiness, bad luck, or Tenma’s complete obliviousness to his affections, as her own heart is set on another classmate, Oji Karasuma. Despite his intense jealousy towards Karasuma, Harima’s primary priority is Tenma’s happiness, leading him to sometimes set aside his own desires to help her, even if it means bringing her closer to his rival.

During the second semester, Harima’s role in the story deepens significantly as he pursues a secret dream of becoming a professional mangaka. He draws manga under the pen name Harima Hario, creating stories that often feature idealized versions of himself and Tenma. He is incredibly embarrassed about this hobby, as it contradicts his tough-guy image. When his work catches the attention of a publisher’s chief editor, he requires an assistant, leading to one of his most important relationships: with Tenma’s younger sister, Yakumo Tsukamoto. Yakumo becomes his secret assistant, critic, and confidant, a situation that creates a web of romantic misunderstandings, as many of their classmates mistakenly believe the two are dating. For her part, Yakumo develops genuine feelings for Harima, but she often suppresses them, believing her sister would be a better match for him.

His other key relationship is with the wealthy and proud Eri Sawachika, who teasingly calls him Hige. Their relationship is a classic love-hate dynamic built on constant bickering and misunderstandings, yet they have proven to work surprisingly well as a team. Although he is often annoyed by her, Harima is one of the few people who treats her with complete honesty, unfazed by her social status, which ironically becomes the foundation of her attraction to him. He remains completely oblivious to her feelings. Harima also lives under the roof of his cousin, Itoko Osakabe, who is also a physics teacher at the school. She enjoys tormenting him about his romantic troubles but cares for him deeply. He also has a younger brother named Shuuji, who has a crush on Yakumo.

Throughout the story, Harima demonstrates several notable abilities. His most prominent talent is fighting, honed through years of street brawling. Though he has no formal training, his raw power, speed, and instinct allow him to fight on equal terms with skilled martial artists. He is also exceptionally athletic and skilled at riding his motorcycle. Later in the series, he inexplicably develops the ability to communicate with animals, a talent he uses for street-side fortune-telling. This unusual ability is tied to his menagerie of bizarre exotic pets, including a pig named Napoleon and a giraffe named Pyotr, who he keeps on the roof of his cousin’s house. His development as a character is tied to the tension between his delinquent past and his aspirations as an artist, as he slowly learns to navigate his feelings and relationships amidst the constant comedic chaos he inadvertently creates.