TBH, from all the dark mangas and webtoons I've read and after years of gathering intensive knowledge on this :P , I think it's highly unlikely that Jaeha is completely innocent. He probably already knows about Yeosob orelse he's way too innocent.
However this ends, I do hope that it reaches a conclusion where every character is happy, but it's only a wishful thinking. ╮(￣▽￣)╭
That would honestly be such a bad twist though. Oh he knew this all along, that just really squeezes all the meaning and bloodshed out of this story. Seeing him horrified of what his younger brother was doing would be more normal and likely hence the title. But the younger brother might persuade him to hurt taeoh, taeoh did torture Jaeha a bit.
But yeah, I want a happy ending too, but that's false hope. Maybe a bittersweet ending like the manhwa Bastard? That would be satisfying enough for me.
It might be a bad twist, but it's a possibility. Remember how Jaeha had a nightmare about Yeosob? It might be a flashback and probably the moment Jaeha realized the truth. He might not have said anything to anyone because they seem to be extremely codependent and he possibly didn't want to lose him.
Again, it's only my guess and probably not what happened. Yeosob sees Jaeha as his most precious person and wants to keep him away from anyone who'd separate them or hurt him. It'd be weird if there wasn't a starting point to all of this. I mean, Yeosob was very young when he met Jaeha. So, such extreme level of possessiveness has to have been there since the beginning. He probably hurt Taeoh too, you're right but Jaeha was likely oblivious and still is.
But I think Jaeha played at least some role in this. He knows how possessive Yeosob is, he might not know that he's been hurting people, but he definitely knows that Yeosob is capable of it.
Aghhh...I hope it's not a tragic ending and Yeosob gets the help he needs because I'm sure that he's a victim too. I want Jaeha to be happy too. *sighs*
Wait, what? It's pretty damn obvious that he knows his brother is not exactly sane. Why would that mean he isn't horrified?
In my thoughts and predictions, Jaeha might not know that he not exactly the same. He might think it's because of Yoseob's past. Basically how Yoseob was taken in, his family hurt him, so Jaeha wanted to protect him. He doesn't notice the weird hings his younger brother does but sees it as just close brotherly affection. But now it is starting to come to him that what he's doing is suspicious.
Please don't be so closed-minded. It may seem obvious to you that he knows about all of this. But if Jaeha really had then why wouldn't he stop his younger brother from hurting his crush? It wouldn't make sense if he entirely knew already and clearly.
I predict that Jaeha is just telling himself that Yeosob is good he's just acting a bit weird. Or a.k.a lying to himself that his dear younger brother would do such thing. I want Jaeha to be happy, I want Yeosob to get some therapy lessons and tgen rejoin his brother as a more sane person, I want yura to find someone who accepts her for who she is, I want taeoh to apologize and become friends with Jaeha again.
But that probably won't happen. I still wish.
There's a war about who's right and who's wrong. You joined that fight but then realized that everyone is at fault in some way (being rude and like a bitch, almost stabbing someone's eye out, bullying etc.). All except Jaeha. He literally is the most innocent child here and the most pitiful.
Judging from the story and how it's going. Jaeha might soon understand what taeoh and yura are talking about or he'll defend his dearest younger brother. If it's the first, then he'll start becoming friends with them, taeoh will make amends and yura will develop more. However this is a dark manhwa so, taeoh and yura will most likely suffer more horrible injuries. It might leave them paralyzed and in the hospital for months. This happens because Yoseob finds out about their plans. Unfortunately Yoseob gets caught, judging from the police scene in the previous chapters. Jaeha is most likely going to live on without the girl he loved, the bestfriend he had, and the brother he cherished. Cause this manhwa is dark so...
If he defends his brother, taeoh and yura will still get hurt, maybe even murdered. Yeseob will be obsessed over his dear brother. Jaeha might realize this and try to escape. Yeosob's obsession might lead to him killing his older brother (me assuming this because I watch movies with crazy people in it and it usually leads to that so maybe?) so that Jaeha stays with him forever. Yeosob realizes this and he's happy. (judging from the fact that when he was interrogated he was happy and calm) because his dear brother is with him forever.
These are just theories, none of them are happy because this ain't a happy manhwa. What do y'all think us gonna happen?