"--- Someday, please serve me." childhood. It was a short relationship of three months when I met him by chance, but Hiina was thrown such words by a boy who became friends. Hiina nodded to the words and promised to meet the boy again and received a silver ring. Ten years later. An unreasonable expulsion sentence given to Hiina who became a royal mage to find a boy who once made a promise. She was kicked out by some aristocrats because she was a commoner, but there is one figure who calls out to such Hiina. It was the second prince, Evan Vel Lost, of the Lost Kingdom, a boy who made an appointment with her more than a decade ago.