Alex is surprised to see someone inside the Billing Department in the hospital, where he is working as the lone anesthesiologist. She looks so stunning and beautiful in her mid-twenties. And yet, she looks mysterious and scary. Out of a sudden, she shows him her real self and discovers that she is his Angel of Dark and Light, better known as Angel of Death.
She meets her assignment and something tugs her heart. She is mesmerized by his uncommon, yet familiar eyes. She then knows that she finds human feelings in this man.
When she decides to leave him in the hospital that day, she feels another fellow Angel of Dark and Light is present and is near her assignment. She is just in time to save Alex from the murderous Lahash. She calls her butler to help Alex to get away from the hospital and to keep him safe.
Azza questions Lahash why he wants to kill her assignment. He explains that he is his order, too. She is told that her assignment is a nephilim that Beelzebub wants his soul to overthrow Lucifer from his throne in Hell.
Since Lahash fails to kill the nephilim, Belial is sent to do the job. However, she perishes by Alex’s newfound powers.
Later on, more and more Angels of Dark and Light come to kill the nephilim, however, Azza, her butler Dantanian and other two nephilims, who are Alex’s brothers, come to rescue him everytime.
Azza and Alex become lovers and spend days and nights making love or they would eat out dinner and have a walk at a botanical garden.
Then Obyzouth, an accomplice of Beelzebub, who is previously Lahash’s lover, perishes by his own hands. He turns against her and the others to protect the nephilim.
However, in the end, he ends up betraying Azza and the nephilim to avenge his lover’s death.
The fight in the human world is finally brought to Hell when Lahash successfully kidnaps Alex to bring him to Beelzebub and take his soul as hostage to overthrow Lucifer.
Azza and Alex’s brothers follow them to Hell and she defeats Lahash by sending him to the Lake of Fire, where he is imprisoned for all eternity. And in the end, she also defeats Beelzebub by stabbing him with her xiphos and sends him along with Lahash when he succeeded to kill Alex by a spell.
Then, they see that all souls from Hell ascend to the sky by a bright light and Alex and Azza are also sucked by that same light and are brought back to Heaven, the original planet, where all souls return to. There, Alex meets God and told him that he and Azza have already learned the lessons they need to learn and thus, they decided to stay in Heaven as twin flames for all eternity…