Eien no Aseria: Spirit of Eternity Sword

Synopsis:

After a plane accident killed their parents, Yuto and Kaori have continued to live together as a family; but while visiting their parents’ grave one day, the duo was unwillingly transported to the world of Phantasmagoria by an unknown power. In this place, spirits take on the human form and humans use them to battle. Yet instead of hospitality, the King of the kingdom took Kaori prisoner and ordered Yuto to fight for him and defeat the enemy kingdom – lest he never see his sister alive again. Now, Yuto must take on the role of an Etorange to wield the sword Motome in order to save his sister, before it’s too late.