TV-Series
Description
Daiya Iruma is a secondary supporting character in the Spearhead Squadron of the Eastern Front. A young man with the blond hair and blue eyes characteristic of the Sapphira lineage, he is described as tall and lanky in build. As a four-year veteran of the battlefield, he holds the position of leader for the squadron's Fifth Platoon and has earned the personal name Black Dog.

Born in the Republic Year 350, Daiya is a year older than most of his comrades, though slightly younger than fellow squadron members Kaie and Kujo. His personal name, Black Dog, evokes European folklore concerning spectral hounds often associated with witches, a symbolic link to his close comrade Anju Emma, whose own personal name is Snow Witch.

Daiya's personality is defined by a contrast between social awkwardness and genuine tact. He is known for finding himself in uncomfortable situations, such as inadvertently barging in on the squadron's female members as they bathed in a creek, an incident that resulted in him being driven off by a hail of thrown objects. Despite these clumsy moments, he possesses a compassionate and insightful side. He is shown comforting Kurena when she expresses frustration over their Handler Lena's well-meaning but intrusive attempts to help the squadron during their downtime. His sensitivity is particularly evident in his long-standing relationship with Anju.

The most significant relationship in Daiya's life is with Anju Emma. The two were assigned to the same squadron upon their initial conscription and served together continuously for four years, including their eventual transfer to the Spearhead Squadron. From their first meeting, Daiya demonstrated a perceptive kindness. He complimented Anju on her hair, which she was growing long specifically to hide the scars on her neck, telling her she should keep it that way. This moment formed the bedrock of a deep friendship, and it is confirmed that Anju held romantic feelings for him, with strong implications that Daiya reciprocated these affections.

As a member of the Spearhead Squadron, Daiya participates in the unit's dangerous reconnaissance and combat missions against the autonomous Legion forces. His role as a platoon leader places him in a position of responsibility, and his years of experience make him a reliable, if not necessarily flamboyant, asset to the squadron. His story concludes during a mission before the eve of the Republic's revolutionary festival. After being mortally wounded by a Self-Propelled Mine, he is euthanized by Shinei Nouzen, becoming the eighth casualty of the Spearhead Squadron. In the anime adaptation, his death occurs as he attempts to rescue a comrade, and his final, unspoken thoughts are implied to have been directed at Anju.