After freeing a slew of women from the devils that have taken possession of their hearts, the "God of Conquest," Keima Katsuragi, is given a new mission: discover the Jupiter Sisters, the goddesses that locked Old Hell in the past. Diana, the goddess who dwells within his childhood friend Tenri Ayukawa, says that they have found refuge in the hearts of the females he previously assisted. Furthermore, if Diana and her sisters are reunited, their power may permanently seal the fugitive spirits away, relieving Keima of his exorcism responsibilities. Though he is first hesitant to take on yet another task, everything changes when one of the hosts is tragically killed.