Rei Furuya, operating under aliases Tooru Amuro and Bourbon, dedicates his life to undercover operations for Japan's National Police Agency Security Bureau. Bullied in childhood over his mixed heritage, he frequently fought until doctor Elena Miyano treated his injuries and became his mentor. Her disappearance motivated his police academy enrollment. As the academy's top graduate, he demonstrated exceptional intelligence and combat prowess, forging close bonds with classmates Hiromitsu Morofushi (Scotch), Wataru Date, Jinpei Matsuda, and Kenji Hagiwara. Joining the Public Security Bureau, he infiltrated the Black Organization as Tooru Amuro—freelance detective and Café Poirot waiter—severing past ties to protect associates while gathering intelligence. Codenamed Bourbon within the Organization, his deductive skills earned Gin's comparison to "a great detective like Sherlock Holmes." Missions included tracking scientist Shiho Miyano and investigating Shuichi Akai's alleged death. Collaborating with Vermouth, he impersonated "Scar Akai" to test reactions. His hatred for Akai stems from Scotch's suicide during Akai's (then Rye) confrontation. Rei believes Akai failed to prevent Scotch's death and exploited it for organizational gain, resenting Akai's FBI status in Japan. His identities manifest distinct personas: Amuro maintains a cheerful, helpful facade as Kogoro Mouri's apprentice, subtly guiding deductions; Bourbon employs secrecy, manipulation, and ruthlessness, endangering others to achieve goals. As Rei Furuya, he prioritizes duty to Japan above all, justifying morally ambiguous actions through deontology—national security overrides personal ethics. Each identity aligns with separate moral frameworks: Amuro with virtue ethics, Bourbon with ethical egoism, Furuya with deontology. Despite methods, he protects innocents when possible, like planning Shiho's extraction instead of elimination, and shows loyalty to colleague Azusa Enomoto. He possesses masterful deduction and observation, uncovering Conan's role in "Sleeping Kogoro" and confirming his identity as Shinichi Kudo through case details only Shinichi and Ran knew. Proficient in martial arts (boxing, jujutsu), high-speed driving, lockpicking, first aid, and tennis, he drives a white Mazda RX-7. Key relationships include fluctuating antagonism toward Akai—grudging cooperation amid crises but enduring hostility over Scotch; protective vigilance over Azusa Enomoto; and mentorship under Kogoro Mouri, initially investigated for Shiho ties before focusing on Conan. His dynamic with Conan involves mutual deception recognition—Conan calls him a "liar" for hidden allegiances, while Rei acknowledges Conan's concealed genius. Character development reveals tension between unwavering duty to Japan's security and his double life's personal costs. He isolates himself to maintain cover yet risks contact with Hiromitsu's family to return mementos, reflecting unresolved guilt. His morally flexible actions consistently serve his perception of justice, positioning him as a complex ally in the broader conflict.