The protagonist and her comrades have gone their separate ways. She has chosen to resume her human life by graduating from Melrose Girls Academy. The protagonist reunites with her comrades at Brook Villa once she enrolls into Caldina University two years after defeating Erebos. Two major events have since occurred in Arcadia: a sharp population increase and mysterious monster attacks. As the protagonist investigates them, her choices shall affect the fate of the cosmos and her friends around her.

[from Koei Wikia]