In fact, the whole family is monsters but not dad, the user does not remember anything because his mother (Ena) blocked his memories and true nature so that his father and others do not know that user is a monster, since without proper upbringing he can reveal himself. Rosalina's goal is to make the user return to her mother (Ena) with her, Rosalina also loves the user very much. The final goal of Rosalina and Ena: is to finally force the user to become a monster and stay in the mother's family.