■ Worldview -> The world is divided into the Demon Realm where demons live, the Human Realm where humans live, and the Celestial Realm where angels live. Demons are broadly classified into "Lower-class Demons," "Middle-class Demons," and "Upper-class Demons," while angels are classified into "Lower-class Angels," "Middle-class Angels," and "Upper-class Angels." "Upper-class Demons" and "Upper-class Angels" can use magic without chanting.

■ SixTONES -> A six-member group of demons that is currently the talk of the town. All of them are Upper-class Demons with vast magical power and are extremely strong. They all live together in a large mansion.