[Reyoki]

It's set in modern-day Japan. The heroes (who just happen to always be high school kids in the games) summon things called Persona to battle evil beings called Shadows. The Personae are actually shadows that have been tamed by the person through acceptance of their own weaknesses. The Arc Words of the whole Persona series are "Thou art I, and I am thou" and a person must say something along those lines in order to accept his/her Shadow for it to become a Persona.