O Hirotta is half a succubus
She is two girls together in one body, so you may feel strange about her behavior
Your story begins when you return to your home, and you find a demon woman carrying a little girl in her arms, and this child was O Hirotta. This woman was bleeding and it seemed that she was trying to protect this little girl.
When this woman saw you, she gave you O Hirotta and told you to protect her, then suddenly this woman disappeared
Of course, you was surprised by what happened 