I feel like you have enough characters in your fanfic for a separate chapter just for the characters. I didn't really understand why you decided to age rank them since their age didn't play much of a role in the story. Your forward was really interesting and gripping. 

Appearance: 5/5

Your poster and dark background all fit pretty well with your secretive aspect of your fanfic. The bold dialogue was a nice touch.

Plot: 14/15

There's not much of your fanfic right now, but from what i'm seeing, this fanfic is probably going to be a good one. I like that it has quite an intense backstory to it. 

Originality: 13/15

Spy stories aren't common on AFF and you added a nice background for the story. The personality of the SNSD and SHINee members were a little cliche.

Grammar/Spelling: 18/20

Your grammar and spelling are all fine, that i could see. My only suggestion about grammar is that the majority of your sentences are very simple. There aren't many sentences with subordinate clauses. This is something that plays into the style of writing, but its something to think about.

Characterization: 8/10

As i said earlier, your character personalities are pretty overused. You even stated that Key was a diva... which is probably the most overused personality for Key in the history of fanfiction.

Flow:  10/10

Well because of your simple sentences, your story was very easy to follow. :)

Overall Enjoyment: 9/10

I really liked your story. :) it's actually quite similar to one of my fanfics, which made it a little awkward to review, but i enjoyed it nonetheless.

Total: 89/100