Jirou Tomitake presents himself as a freelance photographer frequently visiting Hinamizawa to document birds and local festivals like Watanagashi. Villagers including Keiichi Maebara, Rena, and Mion recognize him as an affable outsider who shares folklore about Oyashiro-sama's curse and the dam project. His public image features a yellow camera, brown cap, green sleeveless shirt, military trousers, belt bags, and dog tags. Secretly, Tomitake is a First Lieutenant in the Japan Self-Defense Forces, formerly a sniper reassigned as an instructor after an eye injury. Recruited by the covert group "Tokyo," he audits the Irie Clinic's Hinamizawa Syndrome research, reporting progress to his handlers while coordinating with Dr. Kyousuke Irie and Miyo Takano. His relationship with Takano fluctuates across timelines. Publicly, they pose as lovers through photography lessons and dates, though Tomitake distrusts her occult fixation. In Minagoroshi-hen, she recruits him to kill Furude Rika and trigger the "Great Hinamizawa Disaster." When he refuses, Takano reveals his L3-stage infection from tainted vaccines and injects him with H-173, inducing fatal Level L5 throat-clawing—a recurring outcome in most arcs. Matsuribayashi-hen diverges when Rika warns Tomitake of his fate. He uncovers Takano's embezzlement and alliance with the "Mountain Dogs" paramilitary group. Teaming with Rika, Irie, detective Kuraudo Ooishi, and Mamoru Akasaka, he thwarts her plot. After Mountain Dogs capture him, Irie and Shion Sonozaki lead his rescue. Tomitake then mobilizes Tokyo's "Bloodhounds" agents to arrest Takano and dismantle the conspiracy. Later sequels show reconciliation: Tomitake safeguards a remorseful Takano as a witness during investigations. They eventually return to Hinamizawa together, implying a shared future. Trained as a sniper, Tomitake demonstrates combat precision—like disabling pursuing vehicles—while his photography hobby demands similar patience and steady hands. He maintains calm professionalism but displays awkwardness with women and perverted humor in lighter moments. His role evolves from a repeated victim to an active conspirator, pivotal in ending the syndicate orchestrating Hinamizawa's tragedies.