Sunsong Amphipteres are an unusual breed. Due to light interference caused by their magical nature, they don’t seem to be affected by any ambient light source. However, when struck by direct sunlight, they shine a brilliant gold. They are playful and ever in flight; their ethereal and mysterious appearance and the fact that they are usually only seen at a distance have led many to believe they are a symbol of hope and good fortune.

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.

Kaikou's name means "mysterious light."  True to the nature of her breed, she is elusive and seems to be immune to attempts to catch her.  There is one among the dragons who claims to have spoken to her, although most disbelieve it.  She has come to speak to Seiun the nebula dragon as he stargazes alone at night.  He cannot see her in the darkness, although he says he can visualize her by her unique aura.  He was the one who revealed her name, although he does not disclose the matters which they discuss.