This is pretty cool, I like where its going, please write more. :)

I'm not sure if you know this, but someone named M.S. Dae has a story with the same title and summary as you.
Just thought you ought to know...

...Kaoru's the main character right? YES! I love Kaoru! Please update soon! Dude, you must get tired of people typing that...it's so...repetitious.

I found the phrase that you used to describe how Kaoru feels, like they were walking side by side and Hikaru is gradually out pacing him, leaving him behind. It also portrays that Kaoru holds no grudge with his brother for moving on without him. Nicely written, I look forward to seeing more of the plot.

I was a little confused as to what exactly this story was about, so I looked at the challenge forum... and wow. This looks like it's going to be one crazy, crazy story. xD I'm looking forward to seeing where this is going. It ought to be dramatic, if nothing else.

Don't worry about whether or not you're experienced enough. But one thing I would recommend to a newer writer is to keep your story short, so you don't feel overwhelmed. :)

Wait... I'm confused... what are the pairings?... ^^; It's good, but... who's trying to be paired up with who?