Bright-Breasted Wyverns are a breed of dragon easily recognized by their bright red markings. They are a small breed, only the size of a full-grown man. However, they have developed poisonous barbs on their feet to make up for their size. Their coloration is used to warn off potential predators of the danger, and is also used to attract mates. They are very social, and can often be seen preening in large groups.

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.

Yukine is a strong-hearted dragon who cares deeply for all of his clan members. He can be trusted to keep any promise he makes and to perform any task he is given. However, his judgment is sometimes clouded by his ego and pride. He loves flying and talking with his best friends: Ushina, Kyokane, and Daichisu.