Kuromueina is the first demon Kaito met, and one of the Six Kings. In truth, she is the strongest member of the Six Kings, with the others being individuals she raised. She is the half body of Shallow Vernal, who split her soul, at the same time as she created the world. Kuro was created with purpose of observing the world and coming to a decision whether to destroy it, or Shallow Vernal, who created it.