Carrera is a talented devil who effortlessly collects rare souls, unlike her struggling and jealous peer, Mercedes. When a human man summons Carrera, he makes a surprising request for sexual intimacy as his sole desire. Although the contract dictates that Carrera must claim his soul upon his satisfaction, she finds herself so enamored with the experience that she chooses to let him live, only to discover that failing her duty carries a heavy price from her superior, Alphina.
After being imprisoned in Hell for refusing to claim a human soul, Carrera shares an intimate encounter with Mercedes before returning to her duties. However, as souls mysteriously vanish from the cycle of reincarnation, Carrera's latest summoning to the human world puts her directly in the crosshairs of the Warrior Angels, who seek to punish her for violating the laws of the universe.
After Carrera is kidnapped by warrior angels for a "purification" ceremony, Ogawa summons the devils Rati and Alphina to save her. Determined to rescue her himself, Ogawa forms a new contract and travels to Heaven alongside Alphina and Mercedes. Following a clash with the angels, Ogawa successfully saves Carrera, leading to an unexpected living arrangement where he is surrounded by the grateful and lustful devils.