Mitsuhiko Tsuburaya is a first-grade student at Teitan Elementary School and a core member of the Detective Boys. Raised by parents who are teachers emphasizing formal speech, he consistently uses polite language and honorifics like "-san" for everyone, regardless of closeness. He has an older sister, Asami Tsuburaya, approximately ten years his senior, making him the only Detective Boy with a living sibling. Physically, Mitsuhiko possesses a slim build, short brown hair with messy bangs, freckles on his face, and a documented body weight of 20 kg. He typically wears short-sleeved shirts and long pants. He dislikes carrots and consistently eats them last when possible. Mitsuhiko exhibits a scientific, analytical approach to problem-solving, frequently studying science, history, and general knowledge for both enjoyment and practical application. He proactively prepares for contingencies, such as taking notes during investigations anticipating evidence destruction. His knowledge often provides crucial insights during cases, and he feels validated when his studies prove useful. He demonstrates leadership within the Detective Boys, particularly guiding investigations with his reasoning skills when Conan Edogawa or Ai Haibara are absent. While generally level-headed, Mitsuhiko retains childlike traits, including belief in movie monsters and enjoyment of activities like treasure hunting or building snowmen. His romantic feelings create interpersonal dynamics; he held a longstanding crush on Ayumi Yoshida since kindergarten but developed feelings for Ai Haibara after she joined their class. This dual attraction causes him confusion and occasional awkwardness, particularly as Ayumi shows interest in Conan. Mitsuhiko attempts to impress Haibara through acts of bravery, such as protecting her during perilous situations. Key developmental moments include his role in solving the cavern riddle during "The Desperate Revival" arc, his resourcefulness aiding an injured Haibara in the "Mushrooms, Bears, and the Detective Boys" case, and his dedication collecting fireflies for Ayumi and Haibara in "Mitsuhiko's Mystifying Forest"—an act inadvertently leading to an encounter with a serial killer. His observational skills also contributed to solving cases like "Mountain Witch's Cutlery," where he witnessed incriminating behavior. In "The Stranger from Ten Years Later" OVA, Mitsuhiko appears as a 17-year-old high school student and founding member of the Teitan High School Detective Club alongside the similarly aged Detective Boys. When Shinichi Kudo, temporarily inhabiting his 17-year-old body but displaced ten years into the future, encounters the group, Ayumi refers to him as "Conan-kun," indicating their continued association with Conan in this timeline. Mitsuhiko's presence reflects his sustained commitment to detective work into adolescence.