So I watched this drama and it’s nothing like that. They are close in age I think a year or two apart and he…
I agree. Although I must say, they did sometimes have a chemistry that borders on romance. But I think the whole point of that was to show how (overly?) dependent on each other they were. Some of their scenes might have been a little too intimate for normal brothers and sisters, but it's precisely because they're not "normal" (due to how they grew up with only each other).