
Eeeeeey... im confused.... how did he end up tying his older brother Σ(っ°Д °;)っ

So the older brother viewed himself as the shadow and the younger as the sun, and when people saw them together, he felt like he was dragging him away from the sunlight to meet him in the middle. That's why he went further into the darkness (shadow) to keep the younger in the light, and the younger went along with it because it's what his brother wants. It's just my opinion though
Seriously, 99% of first love ends up getting broken hearted