Genta Kojima, a Teitan Elementary student and founding member of the Detective Boys, helped establish the group following early adventures involving a haunted mansion and a hunt for stolen Italian gold coins. Though he loudly proclaims himself leader, the team instinctively relies on Conan Edogawa’s deductive skills during cases. His brash impulsiveness frequently steers the group into danger, yet he reveals steadfast loyalty and courage when defending friends in perilous moments. Residing above his family’s liquor store with his parents and grandmother, Genta idolizes his father, Genji—a proud "Child of Edo" whose temporary entanglement in a criminal case ultimately strengthens their familial bond. He shares a tight-knit friendship with classmates Ayumi Yoshida and Mitsuhiko Tsuburaya, harboring a quiet crush on Ayumi that sometimes sparks rivalry with Conan. While cordial with Ai Haibara, her composed intellect initially dampens his usual boisterousness around her. Renowned for his bottomless appetite, Genta habitually calculates expenses in units of unagi donburi, his beloved dish. Frequent linguistic blunders—particularly food-related kanji misreadings—invite good-natured ribbing from peers. Later materials hint at a potential shellfish allergy, though this remains unverified. The TV special *Episode One: The Great Detective Turned Small* reimagines the group’s origin, featuring Genta in a spirited soccer match with Ayumi and Mitsuhiko instead of the original mystery coaster incident, underscoring their camaraderie. Consistently portrayed as the team’s boisterous muscle and comic relief, he balances his self-appointed leadership title with growing deference to Conan’s guidance. Occasional flashes of emotional depth highlight his protective instincts and gradual maturity, reinforcing his role as both troublemaker and dependable ally.