[SeijiSensei]

I'm guessing they go beyond the live-action adaptation by NHK? It ends with

Spoiler:

the fall of the Karsh and the great flood. Balsa ends up with Tanda in his hut.

If there are more stories, do they focus on Chagum and his efforts to build a new country? To be honest, I'd be more interested in that subject than more stories about Balsa.

This article from ANN suggests that the NHK adapted "all ten" of the Moribito novels.