Rachel Moore, known as Ran Mouri in the original Japanese version, is a central character in Detective Conan. She is a sixteen-year-old high school student at Teitan High School and the daughter of private detective Kogoro Mouri and lawyer Eri Kisaki. Her parents separated when she was seven, and since then she has lived with her father, taking on most of the household responsibilities. She cooks, cleans, manages the family finances, greets clients at the detective agency, and generally acts as the practical head of the household, particularly because her father is often careless, financially irresponsible, and prone to drinking. One of her long-standing wishes is to bring her parents back together, although their mutual stubbornness makes that difficult.

Rachel and Shinichi Kudo met in kindergarten, where Shinichi asked her for a paper sakura badge she had made. They became close childhood friends and shared several adventures, including investigating an alleged monster at their elementary school. During a trip to New York about a year before the series begins, Rachel helped save a woman from falling to her death, unaware that the woman was actually a dangerous criminal known as Vermouth in disguise. Because of that act of compassion, Vermouth gave Rachel the nickname Angel. It was also during that trip that Rachel realized she was in love with Shinichi. Soon afterward, Shinichi disappeared while the two were visiting an amusement park, and shortly after that, a small boy named Conan Edogawa came to live with the Mouri family. Rachel agreed to look after Conan at the request of a family friend, and she came to see him as a surrogate little brother. She does not know that Conan is Shinichi in a shrunken body.

In personality, Rachel is kind, patient, and nurturing, and she genuinely cares for the people around her. She values life highly and has shown a willingness to save even people who pose a threat to her, such as the disguised Vermouth, and to protect a hostage-taker from being shot by police snipers. She has a strong sense of justice and idealism, much like Shinichi. At the same time, she has a powerful and overwhelming presence when angered, and her temper can be intimidating. She is hot-blooded and tends to act on impulse, especially when someone she loves seems to have been wronged, which sometimes leads her to jump to conclusions and lash out with her karate. She is not above using that strength to keep her father in line. Despite her toughness, she has an irrational fear of the supernatural and dislikes horror, she is known to cry easily, and she becomes self-conscious when trying to express her feelings for Shinichi. She is also humble about her own attractiveness and often oblivious to the romantic attention she receives from others.

Rachel's central motivation is waiting for Shinichi's return. Even though his absence causes her emotional pain, she chooses to wait for him rather than pressure him, trusting his promise that he will come back. She also wants to reunite her parents and to protect and care for her family. Her role in the story is to serve as the emotional anchor between ordinary daily life and the cases that surround her father's detective work. Her home is the base for many investigations, she frequently becomes involved in dangerous situations, and her relationship with Shinichi gives the narrative much of its emotional weight. Her occasional suspicion that Conan might actually be Shinichi creates recurring tension, though Conan always manages to deflect her doubts with help from allies.

Her key relationship is with Shinichi Kudo, her childhood friend and eventual boyfriend. She waited for him for a long time, and the two became an official couple after Shinichi confessed to her in London and she responded with a kiss during a school trip to Kyoto. With Conan Edogawa, she is caring and protective, treating him like a younger brother and looking after his wellbeing while sometimes noticing that he resembles Shinichi. With her father, Kogoro, she is the responsible one who manages the household and keeps his bad habits in check despite loving him. Her relationship with her mother, Eri, is affectionate but complicated by the separation, and Rachel consistently tries to reconcile the two. Her best friend is her wealthy classmate Sonoko Suzuki, who often teases her about her relationship with Shinichi. She also develops friendships with Kazuha Toyama, Heiji Hattori, and Masumi Sera. Her encounter with Vermouth in New York creates an unusual bond, as the criminal comes to view Rachel as precious and hesitates to harm her.

Over the course of the series, Rachel develops from a girl quietly hiding her feelings into someone who confidently considers herself Shinichi's girlfriend. His confession in London and the later confirmation of their relationship mark major steps in her personal growth, giving her greater security in his intentions. She becomes more trusting and emotionally open while continuing to carry the household and care for those around her.

In terms of abilities, Rachel is an exceptionally skilled karate practitioner. She began training after seeing a national champion at age ten, and by the start of the series she is the captain of Teitan High School's karate club and has won championships at both the prefectural and regional levels. Her striking power is extraordinary, allowing her to punch deep dents into metal poles, kick through doors, and defeat armed criminals and even professional fighters in combat. She also has quick reflexes, once dodging a bullet fired at close range, and she is physically agile enough to perform acrobatic movements. She is perceptive and resourceful, occasionally solving cases on her own and staying calm in crises such as hostage situations or fires. However, she can struggle against overwhelming numbers or top professional fighters, is vulnerable to surprise attacks such as stun guns, and can freeze when confronted with something supernatural.