Aoi Sangu

Kureto's servant. Rank: Colonel. Age: 25. The eldest daughter of the prestigious Sanguu family and Mitsuba's older sister. Like Mitsuba, she is characterized by her blonde hair, rumored to be a curse from their ancestors. Her demon weapon is a sword called "Chijiryu."

She has earned Kureto's immense trust due to her exceptional skills, self-sacrificing dedication, sharp and calm judgment, and strong sense of caution. Like Kureto, she has a ruthless personality and does not hesitate to kill humans for his sake. She harbors feelings for Kureto.

She regards her younger sister Mitsuba as "incompetent" and, under Kureto's orders, attempts to offer her as a sacrifice to activate and control the "Seraph of the End" at Nagoya Airport. Even after Mitsuba survives and defects from the army, she calls her a "traitor" and publicly declares that she has no sister when Mitsuba returns to the Japanese Imperial Demon Army.