Tribes by Carmen Webster Buxton
Hob is a slave. Jahnsi is a mercenary, a damsel who never needs rescuing. They both live on Mariposa, a world founded as a prison colony, where all-male or all-female tribes are the only government there is. A person’s tribe demands loyalty and service but provides protection. A girl baby always has a tribe but when a woman can’t find a man to claim her son, she has to abandon him, and the infant can then become someone’s slave.
Hob has nothing to lose when he meets Jahnsi. For the first time in a long time, Hob finds first compassion and then something much more. Jahnsi is horrified by the injustice on Hob’s life. But as she and her family struggle to keep him hidden and safe, someone from off-world begins a manhunt through Mariposa’s slave quarters, looking for a very specific slave.