Kenshirō Daimon is a 36-year-old police officer who works alongside his younger twin brother, Koshiro Daimon. Both brothers harbor deep resentment towards taxi drivers, specifically Hiroshi Odokawa, stemming from their parents' deaths in a hit-and-run traffic accident caused by a taxi driver during their childhood. This traumatic origin is revealed through Kenshiro's flashbacks and Koshiro's conversations.

Kenshiro presents a firm, cool, and cynical demeanor, contrasting sharply with Koshiro's more talkative and justice-driven personality. He exhibits strong protectiveness towards his brother, frequently mitigating the fallout from Koshiro's impulsive remarks. Professionally, Kenshiro demonstrates meticulous attention to detail, exemplified by his repeated stops to question Odokawa during their investigation into the gangster Dobu.

His unresolved trauma fuels a hidden allegiance with criminal elements. Kenshiro discovers that Dobu's yakuza boss, Kuroda, funds a foundation supporting orphans of traffic accidents—the very foundation that aided him and Koshiro after their parents' death. Motivated by a sense of obligation towards this benefactor, Kenshiro secretly aids Dobu. He shares confidential police information, obstructs investigations, steals a crucial data chip from Odokawa's taxi dashboard camera containing potential evidence against Dobu, and delivers it to the gangster while warning Odokawa against police involvement.

Kenshiro's actions create significant tension with Koshiro once his collaboration is uncovered. After Koshiro shoots Dobu during a warehouse confrontation, Kenshiro covers for his brother's absence to prevent a mandatory firearm inspection. Ultimately, Koshiro arrests Kenshiro for his criminal ties.

Due to Odokawa's visual agnosia, Kenshirō is perceived as having a meerkat-like appearance. His actual human form remains unseen in the series, though he presumably resembles his twin brother.