Azusa Enomoto, a 23-year-old Café Poirot employee stationed beneath the Mouri Detective Agency, balances her café duties with occasional case referrals to Kogoro Mouri, typically involving misplaced phones or cryptic messages. Renowned for her approachable demeanor, she aids police investigations and connects with patrons, exemplified by her temporary guardianship of Taii, a calico cat wrongly assumed stray, which she helped reunite with its owner. Her loyalty to family emerges when her older brother, Sugihito Enomoto—a 27-year-old real estate agent—is framed for murder, prompting her to infiltrate perilous situations to clear his name. Though attacked during the inquiry, her persistence aids in unmasking the true criminal.

At Café Poirot, her colleague Rei Furuya (alias Tooru Amuro) shares a strictly professional rapport with her, dismissing workplace rumors of romance. Unaware of Amuro’s covert roles as a Public Security agent and Black Organization infiltrator, Azusa navigates their interactions with trust. Her reliability extends to assisting the Detective Boys and regulars, though her ties to cases occasionally draw danger: she is once kidnapped to manipulate Sugihito and later impersonated by Vermouth during a Black Organization scheme.

Azusa’s name, inspired by the Azusa River and catalpa tree symbolism, mirrors her steadfast nature. Her bold defiance of authority to protect loved ones contrasts with her cooperative stance toward law enforcement. A self-proclaimed admirer of Kaitou Kid, she adopts the alias "The Water under the Moon" online. While her visual design evolves across adaptations, her essence—a blend of compassion and resilience—remains unchanged.