Title: 5/5
Okay, wow.  This title is definitely eye-catching.  It feels like a comedy, which, according to your tags, seems to be an almost accurate description of the story.

Description/Foreword: 6/10
For your description, everything from the rating to the authors note should actually be in your foreword, believe it or not.  Those types of things are better fit in your foreword, as you don’t want your description cluttered with things that aren’t as interesting as the actual description.  The actual description has its strong points, but it also has some grammar issues that aren’t much of a big deal.  Your description sounds too informal, but that is just my opinion and does not affect the results of the review at all.

Your character introductions are unnecessary; I personally skipped over the words.  Assuming that all of this information will be mentioned in your story, these aren’t needed at all.  Plus, your readers probably know what Hyukjae and Donghae look like.  The only picture you might want to keep is the rabbit, though you could probably make do without that picture too.  If you mention all of the qualities under their names somewhere in the story, they aren’t needed.

Characterization: 7/15
Some of your characters are hard to review because there isn’t enough about them.  The one character that you develop a bit more than the others is Kyuhyun.  Through his actions, you can see that even though Kyuhyun’s a bit on the “evil” side, he loves Hyukjae just as much, or possibly more, than the other boys.  Other than Kyuhyun, you should work on developing Hyukjae and Donghae more.  You’ve set them up in an interesting way; now you just have to take that extra step and make them real.

Spelling/Grammar: 13/30
Keep Korean romanized words to a minimum.  You use words such as “appa”, but that romanization could easily be replaced with “dad”.  Words like “neh” can be changed as well.  In fact, sometimes, romanization is so confusing that it’s easy to spell it wrong.  English is the safer and simpler route.  Words you can keep in romanization would be place names; formalities like hyung, noona, etc.; and words that absolutely cannot be translated without changing the meaning of the word.

Even though thoughts are meant to be informal, you overuse the “informal” in your thoughts.  Try to reduce the caps lock usage in your fanfic, as it makes it harder to read, comprehend, and fully process the information you’re trying to give.

You have some comma errors and the occasional misspelled word, but fixing the romanized Korean words and the caps lock should be your priority when you edit your fanfic.

Flow: 7/10
Your flow, in my opinion, is burdened by the large amount of characters that you have.  There isn’t anything you can do about the amount of characters, but you can transition between the separate storylines smoother to help with the flow.

Originality/Plot: 15/25
The rabbit makes your plot original.  How many stories on Asianfanfics.com do you see with a rabbit as one of the main characters?  I could write a whole essay on the rabbit and its connection to the story, but I won’t.  For the first chunk of your story, the plot isn’t clear.  However, as the chapters go by, the readers are able to see the true plot emerging slowly.  Your plot has a lot of interesting twists, but that may or may not be enough to create a strong fanfic.

Enjoyment: 3/5
Enjoyable, yes.  Second read, maybe not.

Total: 56/100

General Comments:
You need a lot of editing and revising; may I suggest getting a beta reader or even a co-author?  Besides that, the general ideas are all there, but the fine details are missing.  Try to re-read your fanfic and pick out certain parts that don’t sit well with you.  Then, edit/revise those parts very thoroughly.  If you want to finish your fanfiction first, then wait until you’ve written the whole thing to go back in and start fixing things.