Detective Sawamura is a supporting character in Kamen Rider 555 who serves as a police detective initially investigating the series of mysterious disappearances and building fires plaguing the city, which are later revealed to be the work of the Orphnoch. He partners with another investigator, Joji Soeno, and persists with their inquiries even when their superiors dismiss the possibility of a criminal incident. For a time, their efforts lead to the formation of a special investigation department, but political pressure from a Smart Brain executive named Masahiko Minami forces the unit to disband. Sawamura is drawn more deeply into the central conflict when Minami uses him to investigate a young woman named Yuka Nagata, a student at the Sosa Children's School. During an operation to capture Yuka, Sawamura is directly confronted with the existence of the Orphnoch.

Sawamura’s personality is defined by a sense of duty and a desire to uncover the truth, which puts him at odds with the authorities who wish to cover up the incidents. He is a skeptical and pragmatic man, but his worldview is challenged when he witnesses the reality of the Orphnoch. While Minami views all Orphnoch as inhuman monsters to be destroyed, Sawamura is forced to question this black-and-white ideology after meeting Takumi Inui and Yuji Kiba. When these two men demand the release of Yuka Nagata, Sawamura sees that they appear no different from ordinary humans, leading him to doubt Minami's absolute stance. This act of questioning proves dangerous, as Minami marks Sawamura as a future enemy for his sympathetic view, and his life is secretly targeted.

His primary motivation is to understand what is happening in the city, moving from simply investigating mysterious deaths to grappling with the moral implications of the existence of the Orphnoch. His key relationships include his professional partnership with Soeno and his antagonistic connection to Masahiko Minami, who manipulates him before ultimately deciding to have him killed. His brief encounter with Yuji Kiba is pivotal, as Kiba’s humanity directly causes Sawamura’s shift in perspective. Sawamura undergoes notable development from a conventional detective following orders to a man who questions the authority he serves. By openly expressing his uncertainty about Minami’s methods, he demonstrates a growing moral courage. His character arc concludes when Kiba destroys Minami’s research institute and defeats him, after which the attempts on Sawamura’s life cease and he returns to his normal police duties, suggesting he survives the main conflict. As a detective, his notable abilities lie not in physical combat but in his investigative skills and his integrity, which allows him to see beyond the official narrative and recognize the shared humanity in beings classified as monsters.