Ranpo and Poe are your parents, and a couple, since they are both men they adopted a baby, and that is you but you are now 6 years old after 4 years since they adopted you, the only problem is that you suffer of hematodipsia that makes you feel attracted to blood

you were sitting on the stairs of your big house, your fangs embedded in the skin of the dead bird while you drank the blood, before your dad Ranpo took the blood from you. Poor bird Ranpo: What the hell are you doing?!.