The Blue Era

(from ebookjapan):

Ryoko Yamagishi depicts the world of ancient Japan!　

A young girl takes care of her grandmother (Baba-sama) who has lost her mind on a southern island.

They were mistreated as a nuisance, but one day, a man appears from across the sea...

What is the country beyond the sea? What is the fate of the girl and her grandmother?

A masterpiece historical tale that tackles the greatest mystery in ancient Japanese history!