Seasonal Dragons take on the characteristics of the season during which they are born. Thus, eggs that are laid in spring match the pink flowers and green buds of spring, and those that are laid in the summer grow to depict the bright green of the forest trees and the yellow of the sun. Eggs laid in autumn display the bright colors of leaves falling from trees, and those that are laid during winter take on the appearance of the icy snow.

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.

His is named after a variety of Japanese deer, the Sika deer, whose name comes from the Japanese word Shika which means "deer". He is the son of Hatsu Yuki and Kaori. He is very fond of the tundra, and enjoys flying into the boughs of the evergreen trees located high on snowy mountains. He is best friends with Hiroyuki, Samui Desu, and Kogoeru. All four of them love to hang out with each other, and fool around in the snow. He is a kind dragon, and is very concerned with the well-being of others. He is well known for leading lost dragons out of blizzards and to safety. It's his kind heart that Yukiko fell in love with. She had injured her foot on a stray root, and Sika helped comfort her until the pain went away. They started to meet after that, just to hang out. But soon they fell in love. The day that they became mates was a joyous day, one that will forever be in their hearts. They are soul mates, and look forward to spending eternity together.