Shetra (シェトラ Shetora) is Adlet Mayer's adoptive sister.
History
Eleven years ago, an epidemic broke out in Hasuna, killing many of its villagers, including the parents of Adlet and Shetra's husband. Since then, Shetra took Adlet in to live with her.
In the last moments before his death, Tgurneu reveals to Adlet that Shetra was in fact killed by Fremy.