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.

The most out-going of K's dragons, Sumirei is what you'd call a "social butterfly". Ignoring the groups and cliques in her dragon family, Sumi' can be found every morning flying her owner's territory and bidding good morning to the rising dragons, all of which have come to accept the social dragon's friendliness, after which she can be found at K's house begging for human food and often preens K's long hair as a show of affection and thanks.

Because of her social nature, she was the first to break through Kor's distant nature and since has become his best friend and mate. Despite being out-going and friendly, Sumirei has had more than her fair share of fights with some of her owner's more grumpy dragons and has shown she is not to be taken lightly despite her size and disposition.