28 years old. Height: 190cm. Former JSDF soldier (Private First Class). He has a bold, larger-than-life personality and doesn't sweat the small stuff. A man of many mysteries. He is a Hybrid Human implanted with the factors of multiple demons by a secret society, specifically carrying the factor of Astaroth, one of the Demon Lords. He is easily liked by children and animals, but he has a cat allergy.

A girl with long silver hair. She looks like a middle schooler. Height: 165cm. Weight: Secret. A Design Human created by the secret society. She was awaiting "disposal" after her data collection was complete when Soji rescued her. She has a tsundere personality.

Full name: Eliza Schneider. 28 years old, German. A beautiful woman with fiery red hair and eyes. Height: 178cm. Weight: Secret. Measurements: B98 W56 H97. Her personality is extremely cold-blooded. She views other humans as nothing more than "tools." As a member of the secret society who was involved in Fou's conditioning, Fou is genetically incapable of defying her.

A penguin that looks like a 2 or 3-year-old girl with a bob cut. Being a penguin, she cannot speak, but she understands human language. She is incredibly gluttonous and a heavy eater, capable of emptying a refrigerator in one sitting. Her personality is like a toddler's, a mix of innocence and selfishness. Like Fou, she is a Proto-Human prototype created by the society. The story begins when she is teleported into Soji's house.

Height: 2m. Weight: Secret. Measurements: B98 W58 H95. A woman with a cold expression. An agent of a certain organization who stalks Soji and his group. She is also a Hybrid Human, possessing the Lilith factor, which acts as a counterpart to the Astaroth factor implanted in Soji.