Ubun 1.0

Ubun take the form of dark-skinned humanoids, identical to humans in most respects save for the broad horns they grow and the thick fur they grow on their chest and hips. Ubun also have more pronounced dentition, more like a monkey's.

Curiously, the ubun are divided into two "blood-castes", relating to their immune systems; "redbloods" have very poor immune systems, while "bluebloods" are somewhat less fragile.

Redbloods and bluebloods are born naturally at approximately a 10:1 ratio overall; blueblooded parents are more likely to produce blueblooded offspring together. However, redbloods are capable of transitioning into bluebloods given the proper conditions, the circumstances of which being of great cultural importance to the species.

Redblooded ubun will undergo a biological shift if they come in contact with the fluids of another ubun with whom they share optimal genetic compatibility. Mixing fluids in this way triggers not only a boost to the immune system (both a general long-term boost and a much stronger short-term one) but also a strong bonding instinct; the ubun consider this to be "true love", and as a result have romanticized the entire process of blood-bonding. While it is far more common for blood-bonds to be formed between a redblood and a blueblood, red/red or blue/blue pairings sometimes produce the same results.

Blood-bonding is a rare occurrence; the genetic match required is uncommon to discover, and the social aspect of mixing between redblooded commoners and blueblooded aristocrats adds an extra level of difficulty in discovering bond-partners.

Natural pheromones play some part in identifying potential bonds, however; statistically, potential bond-pairings are more likely to feel attraction or romantic feelings towards each other than towards non-optimal partners.