Minjae was SAd by the father and the oldest brother, the on that's sick, knew about it cause he saw it but didn't help, he went into his room afterwards. Their shared secret can be they both were SAd but the father or the secret is that the he knew what his dad did. I don't read Korean so I'm just guessing by the flashback in the raws. The middle doesn't know anything which is why he's hostile towards Minjae cause he thinks he's just a trouble maker and reckless and never saw him as a brother. That's why the older one keeps telling him to be kinder to him probably because of the secret they share. The middle brother doesn't know what the dad did which is why we see him taking care of his dad at the hospital, he still sees him as a good dad and wants to make his dad proud, which probably makes me think he was neglected and overlooked and didnt like that his dad showed attention to Minjae whos not blood, not realizing what was happening to him. This is just a theory though from what I'm getting from the raws. I still think the older brother is sus cause we still don't know why Minjae attacked him.
Minjae was SAd by the father and the oldest brother, the on that's sick, knew about it cause he saw it but didn't help, he went into his room afterwards. Their shared secret can be they both were SAd but the father or the secret is that the he knew what his dad did. I don't read Korean so I'm just guessing by the flashback in the raws. The middle doesn't know anything which is why he's hostile towards Minjae cause he thinks he's just a trouble maker and reckless and never saw him as a brother. That's why the older one keeps telling him to be kinder to him probably because of the secret they share. The middle brother doesn't know what the dad did which is why we see him taking care of his dad at the hospital, he still sees him as a good dad and wants to make his dad proud, which probably makes me think he was neglected and overlooked and didnt like that his dad showed attention to Minjae whos not blood, not realizing what was happening to him. This is just a theory though from what I'm getting from the raws. I still think the older brother is sus cause we still don't know why Minjae attacked him.