Let's talk about how everyone ended up.
Kagome returned to the Modern World, and the disappearance of the Shikon Jewel also took away her ability to travel between the two eras through the Bone-Eater's Well...
Inuyasha waited quietly for her, living in Kaede's Village with Sango and Miroku (← married), occasionally slaying a demon...
Three years later, Kagome finally returned. After gaining her mother's understanding, she still chose the Warring States, staying with Inuyasha forever, even though she would never be able to see her family again...
Kikyo continued serving as a shrine maiden, traveling from country to country, destroying demons that did evil and helping people in need...
After talking things over with his sister, Kohaku insisted on returning to Kikyo's side to train, bringing along his little childhood sweetheart, Rin...
Naraku... oh, that poor fellow... I couldn't bear to talk about him...
As for Sesshomaru and Han, they returned to Yokyu Castle in the Western Lands, though they still often ventured out on their travels. Several hundred years later, however, Sesshomaru and Han led most of the demons under his command away from this world, which was gradually becoming unfit for demons to inhabit, never to return.
His sword, Bakusaiga, cut open a rift in space. Just as Qiongji had foretold, the demons migrated together to another habitable world to keep their kind from dying out. In that world, he established his demon empire...
As for the demons unwilling to leave, they withdrew into Gensokyo within the Great Hakurei Barrier. A tiny minority who were attached to humans and loved them continued living happily among them, taking great care...