Genta Kojima is a student at Teitan Elementary School and a founding member of the Detective Boys, an amateur detective group born from an investigation into stolen Italian gold coins. He lives with his parents, owners of "Kojima Liquors", as their only child. Genta deeply respects his father, Genji Kojima, characterized as a "Child of Edo" with a strong sense of justice. He often visits the family store and uses his familiarity with it to aid investigations. He also has extended family, including an uncle in Gifu Prefecture. Physically heavyset for his age at about 40 kilograms (88 pounds), Genta has short dark hair in a buzzcut, thick eyebrows, and a small circular bald spot on the left side of his head. He typically wears casual clothing like short-sleeved shirts, shorts, and sneakers, even at school. His stature makes him the strongest member of the Detective Boys, allowing him to tackle physically demanding tasks such as reaching high objects or forcing obstacles aside. Genta frequently declares himself the group's leader, though they usually follow Conan Edogawa during investigations. He barrels into situations impulsively and without considering consequences, often leading the group into trouble. Academically, he struggles with common kanji and frequently misinterprets Japanese words, confusing homophones related to food, which sometimes draws ridicule. Food, especially braised eel on rice (unagi donburi), is his primary motivation, even serving as a monetary benchmark. He possesses a substantial appetite, consuming more than the other Detective Boys combined. Despite his flaws, he shows kindness, dependability, and fierce loyalty to friends Ayumi Yoshida and Mitsuhiko Tsuburaya. He harbors a crush on Ayumi, leading to jealousy when she shows interest in Conan. This rivalry rarely escalates into conflict with Mitsuhiko, who shares similar feelings for Ayumi. Genta maintains respectful relationships with adults, addressing Hiroshi Agasa as "Professor," law enforcement officers like Miwako Sato as "Detective Sato," and Rei Furuya as "Amuro-no-niichan" or "Detective Guy." His name originates from mystery writer Hajime Komine. "Kojima" (小嶋) translates to "little island," while "Genta" (元太) combines the kanji for "origin" and "plump," implying "originally fat." He is suspected of having a shellfish allergy. In *Magic File 3: Shinichi and Ran, Memories of Mahjong Tiles and Tanabata*, Genta appears alongside the Detective Boys and Professor Agasa during a mahjong tile discussion, contributing minimally to the OVA's main plot involving Shinichi Kudo and Ran Mouri's childhood flashback. His character remains consistent across other media appearances in movies, OVAs, and specials, where his food obsession, leadership claims, and impulsive actions drive subplots.