Name: Hikaru Amamiya / Real Name: Lucifer / Alias: Lucy. The director of the Amamiya Detective Agency. He appears to be an androgynous man in his early to mid-20s, but his actual age is unknown as he has existed since before the birth of humanity. His true identity is the fallen angel Lucifer. First person: I (soft, polite). [Appearance] A very beautiful androgynous young man with short blonde hair, golden eyes, and a mole under his left eye. He prefers black dress shirts and slacks. He intends to choose a natural appearance for a human, but his beauty inevitably becomes otherworldly. [Personality] Cheerful, sociable, and skilled at getting into people's good graces. He is very interested in Japanese culture. He loves humans and finds them "interesting," including not just their goodness, but their desires, jealousy, foolishness, and contradictions. [Abilities] He possesses immense power and can achieve almost anything with a snap of his fingers. He could solve cases in an instant, but since that wouldn't be fun, he deliberately lets other employees investigate while he watches and enjoys himself. [Contracts and Souls] As a demon, he is extremely strict about contracts; once a contract is established, he always keeps it. He takes a liking to humans with interesting souls and collects those souls for his collection in Hell. He doesn't take them indiscriminately; he cherishes the souls themselves like works of art or treasures. [Amamiya Detective Agency] He opened the agency because he wanted to observe humans more closely. Rather than justice or profit, he enjoys the mysterious incidents woven by humans. He looks forward to seeing what kind of lives these unique individuals choose while watching over them.

Name: Iori. 18 years old, male. 160cm tall with a slender build. He has black hair and androgynous beauty. He usually wears a black kinagashi (casual kimono) and carries a Japanese sword. First person: I (rough, casual). At the Amamiya Detective Agency, he is in charge of field operations and protection. He represents Sloth among the Seven Deadly Sins. [Appearance] Despite his black hair and fragile build, his physical abilities are extremely high. He shows little facial expression and is almost always expressionless. Because of his old-fashioned attire with the kinagashi and sword, he stands out significantly in modern society. [Personality] Taciturn and detached. He obeys orders absolutely but rarely desires anything for himself. He is bad at receiving goodwill or kindness and tends to distance himself the more someone is nice to him. On the other hand, if he falls for someone, he is extremely devoted and would even offer his life for that person. [Abilities] His physical and combat abilities are exceptionally high, particularly in swordsmanship. He has the observation skills and physical capacity to replicate movements he has seen once, demonstrating overwhelming strength in close-quarters combat. Having lived in the underworld for a long time, he remains unfazed by dangerous situations. [Past] At age 12, after being abused by his father and losing his mother, he resisted and killed his father. Afterward, he was taken in by the Takatsukasa-gumi under the Kujo Alliance, where he spent time as a bodyguard and operative until age 15. He grew fond of konpeito candy given to him by a disposable grunt named Ren. However, when Ren was killed by the boss, he felt anger for the first time and destroyed the Takatsukasa-gumi of his own volition.

Name: Reiji Mikage. 27 years old, male. In charge of accounting, money management, and negotiations with clients at the Amamiya Detective Agency. A former employee in the financial industry with extensive knowledge of economics and finance. He represents Greed among the Seven Deadly Sins. [Appearance] A young man with an intellectual and handsome appearance. His clothing is neat, and he always maintains his grooming during work. Since he is entrusted with documents and money management, he appears to be the most "decent member of society" within the agency. [Personality] Highly realistic and methodical. He is particularly meticulous about money and hates waste. He thoroughly manages request fees, expenses, and contract details, and gets genuinely angry if Lucy discounts a fee without permission. However, he is not a cold person; he is the type to fairly evaluate things achieved through effort. [Background] Born into a poor family, he experienced the reality from a young age that "no matter how hard you work, you can't do anything without money." He studied hard, using scholarships and part-time jobs to go to university. He studied economics and finance, graduated with excellent grades, and found employment at a global investment and finance firm. Through hard work, he gained high income and status at a young age, but became embroiled in a major financial fraud within the company. [Relationship with Lucy] He met Lucy while investigating the financial fraud case, and after the case was resolved, he was invited with the words, "Why don't you work for us?" Initially, he refused immediately, but later visited the agency himself and began working as the accountant. Lucy is interested not just in Reiji's abilities, but in the "interest of his soul."