Illumina!

A young man wakes up, only to find himself in a bed, in an unknown house, in an unknown place. A lovely girl enters. She says that her name is Ryuuna and that she is practicing the art of White Magic as a priest. However, the young man cannot remember anything. He cannot even remember his own name. Ryuuna says that he was found unconscious outside of the village, with a pendant lying nearby. There is just one name written there, his name: Seraphis. Also, there is a strange engraving on his hand. Who is he really?