"In the seemingly utopian world, where joy is abundant and pain is absent, humans live carefree lives. However, this peace conceals horror and suspense. Beneath the bustling upper world lies the lower world that never sees the sun, where the creatures are buried in secrets. The world agreement manipulates the upper and lower worlds to achieve "balance," where the rich get richer and the poor poorer. To maintain this balance, a group of creator gods created a "humanoid weapon" called "Shina," similar to the god of death. She has no identity or emotions, and her sole purpose is to assist in managing the interests of the government, to absorb souls that threaten the government and send them into a black hole.

During a mission, the protagonist meets a mysterious man named Noah, who is not only a human sent by the upper world government but also a member of a secret organization in the lower world. The encounter between the two triggers a new turmoil in this seemingly beautiful world."

Lower World is where all the Gamma and Delta's living place, or every single creatures which is lower level than Alpha and Beta, or punished, they would be send to the lower world and can never going back.

Upper world where's all Alpha and Beta living place.