Ango Sakaguchi serves as a government operative within Japan’s Special Division for Unusual Powers, an internal affairs branch overseeing supernatural threats. Tasked with infiltrating the Port Mafia to monitor its operations, his mission expanded under Mori Ougai’s orders to simultaneously spy on the foreign militant group Mimic, positioning him as a triple agent. This deception fractured his fragile bonds with Port Mafia associates Osamu Dazai and Sakunosuke Oda, culminating in Oda’s death during the Dark Era. Ango’s role in brokering a government-mafia truce triggered this tragedy, irrevocably severing their friendship. His supernatural skill, Discourse on Decadence, extracts residual memories from physical objects, reconstructing past events to trace escape routes or expose concealed truths—an invaluable asset for investigative operations. Post-Dark Era, Ango outwardly complies with governmental directives but privately critiques Chief Taneda’s utilitarian policies, which prioritize collective security over individual lives. This moral tension drives his covert aid to the Armed Detective Agency during the Hunting Dogs Arc, defying official mandates to eliminate them. In the Guild Arc, Ango negotiates alliances with former Guild operatives while navigating strained interactions with Dazai, whose retaliatory car crash leaves him gravely injured. Despite this betrayal, he later supports the Agency by securing Kyoka Izumi’s legal pardon and decrypting Dazai’s coded messages from prison. During the Sky Casino conflict, Ango feigns antagonism toward the Agency to mislead antagonist Fyodor Dostoyevsky, secretly collaborating with Dazai to dismantle the Decay of Angel’s schemes. Their alliance includes extracting vital intel from Mushitaro Oguri regarding the apocalyptic Book. Ango’s appearance—short dark hair, circular glasses, and a faint lip mole—mirrors his bureaucratic persona, typically clad in a pale brown coat and tie. His reserved, analytical demeanor conceals unspoken guilt over Oda’s demise, though he rarely vocalizes emotions. Over time, his loyalty shifts from rigid governmental compliance to clandestine support for the Agency, motivated by a need to atone for past actions and pursue a personal ethical code. Subsequent arcs highlight his strategic ingenuity: manipulating time-altering prisoners to relay Dazai’s instructions and orchestrating infiltration plans against the Decay of Angels. These maneuvers cement his role as a tactically shrewd yet morally ambiguous figure, navigating bureaucratic obligations and residual allegiance to former allies while seeking redemption through calculated, behind-the-scenes influence.