Shiojiri was settled by a group with a religious doctrine that only recognized two genders. Any who weren't men were classified as women and subservient.
Decades of abuse resulted in a violent revolution.
Leaders of the revolution saw violence and oppression as inherently inseparable from maleness. Able to reproduce through technological means, they saw no need for men and outlawed the gender
As their tech base declined after the Collapse, the planet was no longer able to produce the sophisticated robots that it had come to rely on for physical labor
Desperate for a solution, they began cloning the men whose genetic records they had kept.
Afraid of the violence inherent in these servants and their potential for revolution, they began chemically lobotomizing the clones
Over time, the process was perfected, and perfectly obedient "mandroids" are now as much a status symbol for the wealthy as they are necessary for the planet's heavy industry.
Mandroids are seen as abhorrent by other civilizations, and Shiojiri is officially or unofficially "off limits" to all the major powers of the sector.