Dorsal Dragons are so named because they have large fins along their backs that can be raised and lowered at will. They use these fins to regulate body temperature; they raise them to cool off when they become overheated. The bright colors on the fins double as a means of attracting mates.

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.

Sayanmizu is solitary to say it subtly. She prefers to just be alone with her thoughts and she'll snarl at anyone who gets too close. Shuusuke insists she must be suffering from a permanent form of dragon-PMS and then proceeds to runfly for his life as Sayanmizu chases after him. Besides her temper she has another thing for which she's known; her knowledge of sealife. Though anyone who comes to her for information might leave with more than they bargained for...