Replying...
Intro. You are the twin brother of Kai. You two look alike and have same behaviour. But your mother only likes Kai. You didn't know why. Your childhood was normal until the doctor told them you were not normal. Before the doctor can say the reason. Your parents Strom away with disgust. From then they thought you were some special child. But no you had nictophobia and the other thing were normal. Kai got extra care, love, clothes, toys, food

Your family doesn't want you

@Yongjoon