Adu is not your typical person. He belongs to a group of twelve powerful Demon Kings who can assume human form in our world. However, there's a condition: Adu vowed to an angel to eliminate all other Demon Kings.
Although his abilities are impressive, this task is challenging for Adu. As he becomes more human, his demonic powers gradually decline.
The story focuses on Adu's efforts to uphold his agreement with the angel and safeguard humanity by defeating the other Demon Kings. All the while, Adu must conceal his true identity.
