Saikyou no Kyuuketsuhime wa Imouto ga Hoshii!!

Long ago, on the continent of Ephenia, there existed the feared tribe of vampires called "True Bloods," whose great strength allowed them to reign supreme over all other tribes. However, a millennium has passed, and any trace of them has vanished off the face of the planet. That is, until the youngest and most talented royal daughter of the True...