Detective Nakagawa is a police investigator who appears in the Japanese film Ju-on: The Grudge and its American remake, The Grudge. His first name is given as Kenichi in some sources, and he is characterized as a calm, professional, and determined officer who approaches his work with logic and composure. Nakagawa is driven by a strong sense of duty, initially trying to make sense of a series of bizarre deaths through standard police procedure. As the investigation deepens, his motivation shifts from solving a mystery to a quiet courage, as he eventually accepts that the only way to stop the deaths is to destroy the haunted house at the center of the curse.

In the narrative, Nakagawa enters the story when he and his partner, Detective Igarashi, are called to investigate the house after a social worker is found in a state of shock and her elderly charge is discovered dead. His primary role is to investigate the inexplicable events, questioning survivors like the social worker Rika in the Japanese version and Karen in the American remake. During these interrogations, he conveys the nature of the Ju-on curse to them, describing how a rage-born stain upon a place can lead to death for anyone who enters. A key part of his investigation involves reviewing security footage, an act that directly leads to his own haunting by the ghost of Kayako Saeki, who appears to him from within the video tape.

Nakagawa has key relationships with two main colleagues. He works closely with his partner, Detective Igarashi, throughout the investigation, and they often discuss findings and search for clues together. He also consults a former detective named Yuji Toyama, who had originally led the investigation into the Saeki family murders years prior. It is Toyama who provides Nakagawa and Igarashi with the crucial background of the case, explaining the fate of the family whose rage created the curse.

In terms of development, Nakagawa undergoes a clear transformation. He begins as a skeptical and analytical policeman who seeks rational explanations for the deaths in the house, such as assuming a murder-suicide occurred. However, after witnessing the supernatural events first-hand and learning that three of his own colleagues previously went missing or died while investigating the same case, he arrives at a grim acceptance of the curse's reality. This understanding leads to his final act: deciding to burn the house down to destroy the curse once and for all. His notable abilities are those of a seasoned detective; he is a capable investigator, skilled at gathering evidence, conducting interviews, and piecing together a case. Ultimately, he is also portrayed as having the resolve to take extreme measures, even at great personal risk, to protect others. His fate is sealed when he enters the house with gasoline, only to be distracted by a ghostly vision of Takeo Saeki drowning his son Toshio. When Nakagawa attempts to save the ghostly boy, he is attacked and drowned by the spirit of Takeo. His death symbolizes the complete failure of human logic and courage against the supernatural and inevitable spread of the grudge. It should be noted that while the user requested information on an "anime" character, the available information consistently identifies Detective Nakagawa as a character from live-action films.