Mitsuhiko Tsuburaya, a first-grade student at Teitan Elementary School, serves as a core member of the Detective Boys—a group born from adventures involving haunted mansions and stolen gold coin hunts. Raised by schoolteacher parents who instill formal politeness, he consistently addresses elders with "-san," reflecting their disciplined upbringing. His older sister, Asami, is nearly a decade his senior. Driven by a scientific mindset and avid reading habits, Mitsuhiko tackles mysteries through empirical reasoning and meticulous preparation. His ever-present notebook captures critical clues, aiding cases where evidence vanishes. This foresight shines when deciphering riddles, crafting makeshift medical supplies, or planting coded messages. Despite his analytical rigor, he embraces childhood joys like treasure hunts and snowman-building, blending curiosity with playful teamwork. Romantic feelings for Ayumi Yoshida and Ai Haibara emerge in a non-canon movie, where he confides in Ran Mouri. The "Mystifying Forest" arc sees him risking danger to collect fireflies for both girls, inadvertently confronting a fugitive. Later, in *The Scarlet Bullet*, he aids in rescuing a kidnapping victim during a World Sports Games event, cementing his active investigative role. Mitsuhiko avoids carrots, relegating them to his plate’s edge during meals. His disciplined exterior, shaped by familial expectations, occasionally cracks—such as when a suspect’s cleaver-sharpening unnerves him. Over time, his growing confidence in case-solving solidifies his status as the Detective Boys’ steadfast third-in-command.