Sachirō Hirugami is a second-year student at Kamomedai High School and the starting middle blocker on the boys' volleyball team. He hails from a family of accomplished volleyball players, including his older brother Fukurō Hirugami, captain of the Schweiden Adlers, and older sister Shōko Hirugami. This background created early expectations for his own excellence in the sport. Physically, he possesses wavy light brown hair, matching eyes and eyebrows, a tall stature, and a lean, muscular build. Hooded eyelids and a consistently calm expression define his appearance. During middle school, he wore a buzz cut. At Yurisei Junior High, Hirugami developed an intensely perfectionist approach to volleyball. He criticized himself relentlessly for mistakes, engaged in rigorous training, and studied physical conditioning books to minimize errors. His efforts earned him an Outstanding Athlete Award, yet dissatisfaction persisted. Pressure culminated in an incident where he scraped his knuckles against a stone fence, drawing blood, after a loss. Kōrai Hoshiumi stopped him; Hirugami tearfully confessed he might not actually like volleyball. Hoshiumi reassured him that quitting was valid if burnt out. This moment marked a pivotal shift, allowing Hirugami to adopt a more relaxed attitude. As a high school player, he is renowned for his composure and observational skills, rarely fazed or distracted during matches. Nicknamed "Hirugami the Immovable," he anchors Kamomedai’s blocking strategy with exceptional read blocking. This skill involves real-time play analysis, ignoring decoys, and swift reaction to the ball’s trajectory—abilities noted to rival elite blockers like Aone. He demonstrates tactical awareness, such as targeting opponents under psychological pressure, exemplified by his difficult jump float serves against Karasuno’s ace, Asahi Azumane. His serving technique involves a float serve that changes trajectory suddenly, comparable in difficulty to Atsumu Miya’s. During the Spring High National Tournament, Hirugami’s interactions highlight his role as a stabilizer, particularly curbing Hoshiumi’s impulsiveness. He openly taunts opponents and teammates but maintains a mature demeanor for a second-year. Against Karasuno, he analyzes and adapts to Shoyo Hinata’s evolving techniques like the minus tempo quick and broad attacks, acknowledging their challenge. His blocking remains formidable, but he admits fallibility when outmaneuvered. Off the court, Hirugami retains his calm disposition and handles responsibilities like managing Hoshiumi’s media interactions. By November 2018, he is a fifth-year veterinary student, indicating a life path distinct from professional volleyball. He follows volleyball events retrospectively due to academic commitments but maintains connections through his brother’s career. His relationship with Hoshiumi remains central, rooted in their middle school encounter. Hirugami often acts as a grounding influence, reflecting their shared history and mutual growth. This dynamic underscores his broader theme: finding balance between passion and personal well-being, free from external expectations.