Fire Emblem Three Houses

From the introduction:

Ages ago, the goddess descended from the heavens and alighted in the red canyon, Zanado. Around her sprung up civilization, some created by her own hand and some called to her side. By all accounts it was an idyllic and peaceful time. However, it was not to last. As people are wont to do, there was conflict. Violence. Foreign powers looked to the land of Fodlan and wanted it for themselves. The goddess empowered a man by the name of Nemesis to defend Fodlan, alongside ten Heroes, four Saints, and her own daughter, Seiros.