Physiology

Howaru’s humans are basically identical to our Earth’s homo-sapiens. There are, however, a few small differences. They are never explained in the manga, but are very visible:

1. The most specific of these distinctions is the effect that testosterone and estrogens have in this world. While estrogens make women more aggressive than their male counterparts, testosterone makes men emotional and moody.

2. Both males and females seem to have exceptionally athletic bodies. Most young adults have toned and defined muscles, and seem to be more agile, strong and resistant to pain than our world’s humans. It is not explained whether this is a genetic characteristic or simply a result of the harsh conditions of life in the planet.

3. Howaru’s humans have hair only on their heads (including beards in males). All other areas of the body are totally hairless.

4. Slaves seem to have exceptionally resistant soles, probably because they developed thicker skin in that area due to walking barefoot since birth.

5. All humans seem to be bisexual. Although this is never mentioned, we can see that most characters engage in sexual relations with people of both genders.