Daiya Iruma, codenamed Black Dog, commands the Spearhead Squadron’s Fifth Platoon. A member of the Sapphira ethnic group, he bears blond hair, blue eyes, and a tall, lean frame, clad in scavenged desert camouflage fatigues like his comrades. His demeanor blends compassionate intuition with social clumsiness, often landing him in mishaps—such as unwittingly disturbing female squadmates during private moments, provoking swift retaliation. Yet his emotional perceptiveness shines through quiet acts of care: soothing Kurena’s frustrations over external meddling, praising Anju’s scar-concealing hair with deliberate kindness, and forging profound bonds with his unit.

Drafted into the Republic’s military alongside Anju Emma in Republic Year 350, he remained her steadfast companion through four years of service before their transfer to Spearhead Squadron in RY 367. Their intertwined codenames—Black Dog and Snow Witch—echo European folklore’s mystical partnerships, symbolizing their nuanced dynamic where Anju subtly guided their relationship. Shared glances and unspoken affections hinted at deeper mutual longing, unresolved by the time of his death.

During a Legion assault, a Self-Propelled Mine inflicted mortal wounds on Daiya. Adhering to squadron protocol, Shin ended his suffering, making him Spearhead’s eighth battlefield loss. His absence reverberated through the unit, etching lingering grief in Anju, who carried silent love for him, and underscoring the war’s relentless emotional toll.