Responses
If your surprise is caused by the fact that you do not know that there is a middle brother, then I inform you that this manhwa is a spinoff of another.
If by my observation about me and my sibling, then I mean that our psychological problems are also similar, I mean my sibling and I, like these guys, have similar problems with each other. But, fortunately, my sibling and I have problems with our heads that are a million times more harmless.

And here I was thinking that the older brother was less fucked up then the middle bro... well, I guess me and my older sibling are too fucked up in the same way. ╮( ̄▽ ̄)╭