Kinji Tōyama, born July 16, 1991, possesses the Tohyama family's Hysteria Savant Syndrome. This genetic trait activates under sexual arousal or intense emotional stimuli, amplifying his cognitive and physical abilities approximately thirtyfold. In this heightened state, his reflexes, speed, strength, and logical processing reach near-superhuman levels, enabling feats such as deflecting bullets, executing supersonic attacks, and rapid tactical analysis. However, the syndrome alters his personality, making him compulsively protective of women, seductive, and overly confident—a stark contrast to his normal demeanor that often results in subsequent embarrassment. A key limitation prevents him from directly harming women, though he can restrain or disarm them. Originally an S-Rank Assault student at Tokyo Butei High, he transferred to the Inquesta department after his older brother, Kinichi Tohyama, was reported killed on a mission. Public ridicule surrounding his brother's death led Kinji to reject his family legacy and plan to quit the Butei profession. His official rank dropped to E due to missed examinations, masking his true combat potential. Traumatic middle school experiences, where female classmates exploited his Hysteria Mode to manipulate him as their "personal ally of justice," fostered his cynical, anti-social attitude and distrust of women. His resolve to leave the Butei life faltered when Aria H. Kanzaki saved him from an attack by the "Butei Killer." Forced into partnership with her, he became involved in her quest to clear her mother's name. During their missions, he developed romantic feelings for Aria, lowering the threshold for his Hysteria Mode activation around her. This manifested when he kissed her to both calm her and trigger his enhanced state during a crisis. His relationships include his childhood friend, Shirayuki Hotogi, whose obsessive affection overwhelms him, and Riko Mine, a fellow Inquesta student. Riko initially betrayed him as the Butei Killer but later became an ally, revealing Kinichi was alive and part of the criminal organization IU. This forced Kinji to confront his brother in combat to protect Aria. Following these events, he formed and led Team Baskerville, comprising Aria, Shirayuki, Riko, and Reki. Despite his growing leadership role and acceptance of his Butei identity, he continued grappling with his desire for normalcy, especially after recognition by entities like the U.S. military and Intergovernmental Armed Detective Alliance. After retiring from Butei High, he established the Tohyama Warrior Office to maintain his Butei license while distancing himself from the academy. He later stepped down to focus on college entrance exams, though his connection to the Butei world persisted. His combat equipment includes a modified Beretta 92FS Inox (the "Kinji Model"), a butterfly knife, and later, a burst-fire Desert Eagle inherited from his father and a scramasax blade (Ragnarok) once owned by Sherlock Holmes. Wielding these tools simultaneously during Hysteria Mode earned him the title "Quadra of Mimicry." His tactical approach prioritizes non-violent resolutions unless absolutely necessary, adhering strictly to legal and ethical codes. Occasionally, he crossdresses as "Clomaetel Belmondo" for missions, adopting a more feminine demeanor that sometimes lingers afterward. His genetic half-siblings include Kinzou Tohyama (GIII), Kaname, and Kanade, though their interactions are minimally documented. His journey evolved from a disillusioned student seeking ordinary life to a reluctant hero who accepted his unique abilities while striving to redefine his purpose beyond his lineage.