Emilia Justina was born to her parents, an ordinary farmer named Nord Justina and the archangel Lailah. Knowing she had committed a taboo by birthing a child to a human, her mother fled, leaving Emilia to be raised by her father on his farm located somewhere on the Western Continent. During Satan's conquest, the child lived a peaceful life with her father. Despite fearing the day they would be accosted by the encroaching demon army, he assured her that their village would be protected by the Church, putting her mind at ease. Her life changed drastically one afternoon when representatives from the Ente Islan Church arrived at her home to train Emilia as the Hero who could free the world of the Demon King Satan. Although reluctant at first, Emilia's motivation was fueled when she received news of her father's apparent death when the Demon King's army laid waste to their fields only days after her departure. In reality, Nord Justina was taken by Lailah and hidden safely on Earth during this time, though Emilia remained unaware of her father's true fate.