Teru Mikami, a criminal prosecutor driven by an unyielding sense of justice rooted in childhood trauma and bullying, developed a binary moral framework categorizing individuals as “good” or “evil” after being raised by a single mother. Her death in a car accident that also killed his tormentors cemented his belief in retributive justice, fueling his career in law and eventual worship of Kira as a divine enforcer of moral order. Chosen by Light Yagami as a proxy to evade suspicion, Mikami inherits Gelus’s Death Note and trades half his lifespan for Shinigami Eyes through Ryuk. His fanatical devotion to Kira mirrors religious zeal, viewing Light as an infallible deity. Rigid routines—meticulous note-writing, daily gym sessions, and an obsessively ordered lifestyle—render his actions predictable, enabling Near to replace his Death Note during the final confrontation. The *Relight 2* OVA diverges from the manga: Mikami kills dissenters during a televised debate, contradicting Light’s usual avoidance of innocent casualties, and collaborates with Kiyomi Takada to eliminate Near’s SPK allies. The manga instead attributes the SPK’s deaths to Mello’s mafia. The OVA adds a surreal sequence hinting at Mikami’s suicide, mirroring his anime demise. Psychological instability surfaces in his ritualistic chanting of “delete” while writing names and his spiral into madness post-Kira’s downfall. The manga concludes with his death in prison from insanity; the anime depicts him stabbing himself with a pen. Matsuda theorizes Near manipulated Mikami via the Death Note, though this remains speculative. Live-action adaptations expand his role: he deduces Misa Amane’s identity as the second Kira, steals her Death Note, and assists Light in eliminating L. In *Light Up the New World*, he resurfaces as the guardian of Light’s son, whom he kills to claim a Death Note before being fatally shot by police. His intellectual rigor is evidenced by a law-centric library and admiration for historical figures like Winston Churchill. A utilitarian mindset drives his self-sacrifice—trading lifespan for Shinigami Eyes—to purge perceived evil, prioritizing ideological victory over personal survival.