Houtarou was born and raised in the city of Kamiyama, a fictional town based on Takayama, Gifu. He grew up with a minimalistic philosophy, believing in conserving energy by avoiding unnecessary effort. His approach to life stems partly from his older sister, Tomoe Oreki, who frequently gives him advice and has an influence on his decisions.

Before high school, Houtarou’s life was uneventful—he rarely socialized and only did what was required of him. However, this changes when Tomoe convinces him to join the Classic Literature Club, claiming it was in danger of being disbanded. Unbeknownst to him, this decision leads him to meet Eru Chitanda, Satoshi Fukube, and Mayaka Ibara, all of whom challenge his worldview in different ways.

Although Houtarou initially shows little interest in participating, his natural brilliance in deduction and problem-solving makes him indispensable to the club.

Houtarou has a tall and slender build, with messy dark brown hair and green eyes that often appear dull or uninterested. His posture is usually slouched, reflecting his indifferent attitude. His facial expressions are typically neutral or tired, rarely showing strong emotions unless provoked.

He wears Kamiyama High School’s standard male uniform, consisting of a black gakuran jacket with gold buttons, a white undershirt, and dark pants. Outside of school, he dresses casually in plain shirts and jackets, further emphasizing his preference for simplicity and comfort.

Houtarou is best described as apathetic, pragmatic, and highly intelligent. He follows a philosophy of “energy conservation,” meaning he avoids unnecessary effort and only engages in activities when absolutely required. His motto, “If I don’t have to do it, I won’t. If I have to do it, I’ll make it quick.” perfectly sums up his approach to life.

Despite his seemingly lazy nature, Houtarou is highly perceptive and analytical. He has an exceptional talent for solving mysteries, often deducing complex conclusions from minor details. However, he rarely takes initiative, only solving puzzles when pressured by others, particularly Eru Chitanda.

Though he comes off as distant and unmotivated, Houtarou is not unkind. He is polite when necessary and, while reluctant, he does care about his friends. His sarcastic sense of humor is often directed at Satoshi and Mayaka, though he rarely expresses genuine anger. Throughout the series, Houtarou undergoes subtle character development, slowly becoming more open to social interactions and engaging with the world around him.

• Joining the Classic Literature Club
  Houtarou initially joins the Classic Literature Club to fulfill his sister’s request, with no real interest in literature or extracurricular activities. However, upon meeting Eru Chitanda, he is immediately drawn into solving mysteries. His deductive abilities quickly prove invaluable, making him an indispensable part of the club.

• Solving Mysteries
  Despite his reluctance, Houtarou becomes the club’s de facto detective, solving various mysteries ranging from historical club secrets to seemingly trivial school events. His deductions often unravel deeper truths, sometimes leading to unexpected emotional consequences.

• Gradual Character Growth
  Over time, Houtarou begins to question his passive approach to life. His interactions with Eru, Satoshi, and Mayaka gradually push him to engage more with others and reconsider his worldview. One of the most notable moments in his development occurs when he starts to wish for a more colorful and fulfilling life, though he struggles to take the first step toward change.