EDIT: I forgot to give it a grade... I just noticed.

Title (5/5):
The first thing I noticed in the title was the "Faraway" part, I can't pinpoint why exactly but it looks strange as "Faraway" instead of "Far Away" while both mean the same thing and both are technically correct, most people (that I've seen at least) put a space between the two so that's why I kind of stared at it, unsure if I should actually say something or not; I'm conflicted, to say the least. I'm just gonna plop that there and move on to the actual title before I give myself a headache from debating with myself.

The title, while it seems to clearly connect to the story, doesn't really seem unique to me. I've seen a load of titles that have this kind of vibe so I just don't feel very interested. Sure, this can change after reading the description, it usually does, but as the title, I don't think I'd be fully interested, looking away from the ship of course (since I don't really like shipping f(x) with exo, just not my thing), enough but that's just me. Whether it's eye-catching or not depends on who is reading it and what kind of reader they are, that's how it's always going to be so I won't say much about that either.

Description/Foreword (10/10):
First off, I love short descriptions for a lot of reasons but the main one would be: they are more mysterious and (for me) compell me to want to read it so I think the choice of words you used and the description as a whole makes me fairly interested so there's not much to critique here since I do fancy the description as it peaked my interest slightly. The layout of the description is very neat and clean as well and I can appreciate that since it's easy to read and nice to look at.

Plot (50/50):
I've never really read a fanfiction based off of just unread letters so this was something new for me. The plot's conflict is quite obvious, which is good, and you can tell Sehun really has regrets on what he did and how he lost her. I like how Soojung wasn't an idol because it can kind of show that idols can have lives outsides of being a boy band and all that jazz.

I didn't really feel that sad about the ending, if at all, but I could kind of feel the emotions that Sehun had poured out onto those letters, making them seem almost real. Truthfully, I think you did a very good job at executing this plot despite it being shorter than I expected.

Writing Style/Flow (20/20):
As I said above, you really made the letters seem real with the emotion you put into them. So, of course, it's only right for me to say the writing style was very good and you really knew what you wanted to write. I really did feel as if I was reading letters from a boy who realized that he lost something good in his life because of his actions. There weren't any grammatical errors either so everything was practically pristine here.

As for the flow, I can't really comment on this aspect since they were just letters, there's not much 'flow' here, to say the least.

Characterization (10/10):
This section is a bit difficult to speak about since we really only know what we're told about Soojung, we don't actually see or meet her since this is Sehun's story through letters. Though, from what I have read, you definitely know what you were doing when writing this since Sehun's letters, as I said before, did seem real. He felt regret, he realized he didn't show her enough love, and so on like a lot of people in the real world feel. So overall, I think you did a pretty good job at successfully showing his emotions.

Personal Enjoyment (5/5):
Despite the short length, I did enjoy it. I think it was a nice, small, read for someone who is in for light angst (since this really wasn't heavy angst). The letter format was very neat as well and I found it quite easy to read without any issues which is also a plus. I don't really have much else to say about it since there wasn't much to really critique as it's perfect the way it is.

Sorry for forgetting the grade, it slipped my mind. It was a perfect score either way since you executed the plot well!