GH1898 Nen ~Tasogare no Haha no Tame no Pavane~

On a faraway planet, the daughter of a land known as the Keeper of the West was abducted.
Her mother grieved madly, then went in search of her daughter.
A forbidden curse. A magic. This was all that maintained their bond.

[from DLsite English]

Based on Keith Roberts' alternate history sci-fi novel Pavane.