In Eien no Aseria, you play the role of Yuuto Takamine, a Japanese orphan boy who grew up together with his sister Kaori. One day, shortly after an encounter with a mysterious girl, he is transported into another world, called Fantasmagoria. In this there are several kingdoms which fight each other because of a spiritual energy called “mana”. Yuuto discovers that his sister is held captive by the king of the country he was teleported. He has no choice but to fight for this country. He doesn’t know yet that some of his classmates were transported into other kingdoms, all that being part of a plan to use them as mana-hunters, since they can wield spiritual swords native Fantasmagoria are unable to.
The game combines elements of Japanese RPG, strategy, and “dating sim”. Yuuto controls four parties of three characters each. He has to assign strategies to those parties and then send them to fight enemies and to collect mana. The turn-based, first-person perspective battles develop automatically according to your preparations. Yuuto also must fortify the kingdom he fights for, building training grounds, facilities, etc. He’ll also dedicate time to romance, trying to win the attention of one of the many beautiful girls he encounters.