Worlds Apart by Carmen Webster Buxton
Praxiteles Mercouri, known to his friends as Prax, has spent his whole life on the plains of the planet Celadon. He knows nothing of technology; his nomadic people travel in huge wagons pulled by enormous beasts native to Celadon. His culture is based on clans, duty, and obligation.
Rishi Trahn lives on Subidar, a much more populous world with a much higher level of technology. Rishi has inherited her family’s very profitable trading company and in checking up on the business, she travels to Celadon. While sightseeing she is able to avert a disaster for Prax’s clan. In the ensuing celebration, Rishi overdoes the potent local wine and causes a crisis for the clan she saved. As a result, Prax ends up travelling back to Subidar with her, but he is a man lost in a maze of a foreign culture and unknown technology. Rishi, meanwhile, feels terrible for taking him away from his people. But not so terrible that she wants to send him back