Kirie Kawasaki, the heroine introduced in the Investigation Agency's Security Division, shines as the first female chief in history—a supremely confident bodyguard whose sharp instincts surpass conventional notions of masculinity. But one day, agents from the militant extremist group "Ewan no Hikari" (Eternal Yamato's Light) infiltrate the investigation, and due to their devastating actions, Kirie is captured. She is subjected to relentless torture designed to break her mind completely. This torment is no mere spectacle—it marks the first step in a vast conspiracy aimed at dismantling the Investigation Agency and infiltrating the nation's central government.