Princess Marianne from the Pedin Kingdom faces dire consequences after an altercation with Queen Orphelius' daughter leads to her demise. Seeking vengeance from the brink of death, Marianne summons a demon named Yurisina, who aims to make her mark as a full-fledged demon through their contract. However, the task Marianne demands might prove to be a daunting challenge for this inexperienced demon.