Black Dragons are warriors. They are strong and capable in battles of force, but also ample magic users, capable of devastating opponents with their spells. Their bright eyes give them excellent night vision, which is why they generally hunt during the night.

Dragons are highly-intelligent reptilian creatures that—from a human perspective, at least—appear to live forever. Many different varieties of dragon exist, each with their own unique qualities, habitats, and behavior. Adolescence in dragons is usually marked by the growth of a hatchling’s wings, although not all breeds of dragons grow wings and some breeds have other traits that indicate the beginning of maturation. In Galsreim, dragons and humans coexist peacefully.

Like her mother, Makuro, before her, Kuro no Keiyakusha was spoiled as a child. However, she also had her father's sweet temper and became neither demanding nor mean. Instead, she grew up to be dependent upon her parents and still rarely leaves their side.

Makuro practically runs her daughter's life, with her consent. Kuro no Keiyakusha rebelled against her only once: when Makuro forbade her to become Shiroiho's lifemate. Her love for him was so strong that she overcame her fear of her mother's disapproval.