- Voiced by:Yuki Makishima (1st Drama CD),Ayahi Takagaki (2nd Drama CD), Shizuka itou (anime) (Japanese), Shelley Calene-Black (English), Margaret Fawcett (English, Child)
Fujiko Eto is the head of the girl's dorms at Constant Academy, and one of the few people early in the series who sympathizes with Akuto and his situation. In the manga, she is a second-year and a leader of the discipline committee.She became the head of the Eto family after a tragic incident involving her older brother. However, she keeps in contact with him via his reanimated head, which has lost part of his memory, and which she keeps in a fluid-filled jar. In the anime, her brother was killed by an unknown power on the mission, while in the manga, he was executed for failing the mission. She plans to use Akuto's demon powers once he becomes Demon King for her own purposes. Despite her evil intentions of wanting to be Demon Queen, she becomes very attracted to Akuto and realizes she is in love with him, or at least lust, given her sexual actions in the anime.
Her magical powers are mostly based around the use of chemicals and potions, which she throws around like grenades, but she uses a whip, and develops the ability to control some of the demon beasts. She also has a research lab that she hides away in.