Title (3/5)
Your title is not really eye catching. When I read it, I knew that there'll be character death and I kind of knew how the plot goes already. You title is too long too, it looks like a sentence more then a title. But some points for you since it matches with the story and it's not like a random title that doesn't even match with the story/plot.

 

Appearance (-/-)
Not including this as the graphic was made by me.

 

Foreword & Description (10/15)
The description actually sounds like a quote and the way you written it was really good. But if I didn't saw the tags genre, I would actually thought that it's a comedic story. Especially when you bold and capitalized the letters 'Totally Ruined.' 

But I really like the 'It depressing me, driving me crazy' part. It shows that the girl was going through a crazy feeling. 

 

Characters (6/15)
Your description for the characters were not really much since the whole chapter was more about what was happening instead of the description for the characters. And when Myungsoo drop dead on the stage, I can see that you tried to express the girl's and Sungyeol's feelings. The girl's feelings were expressed really good but then I don't really understand why Sungyeol didn't ran to Myungsoo yet. I understand why the girl didn't -Since she was too stunned and she didn't see it coming- but not for Sungyeol. 

But I really liked the part when the girl wakes up from the memory and she's sweating and all; the description was really good. But because of the foreword, you should have just added the girl's feelings and shouldn't add Myungsoo's feelings but it's up to you.

Plot (12/20)
I've seen tons of stories with this kind of plots; the angst-romance type where the boy dies and didn't tell the girl that he has some sort of cancer. I hope that you add more twists in it so that it will be different and all. Like add what happens to the girl in the next ten years- did she move on, did she suffer from depression, did she meet a new guy, etc.

Flow (10/10)
There's not much to say here since it's a dream/flashback. But I didn't really feel like it was too rushed or dragged. 

Language (15/20)
I spotted mistakes here and there- but it wasn't that bad. But the flashback part should've been written in past-tensed since it happened in the past. And you keep jumbling past tense and present tense in the story. You need to work on your grammar too. But it isn't that bad, I still could understand what you were writing. Here are some examples.
 

Originally:
October. It’s raining and here I am… trapped inside of the library –again. With my boyfriend –again. To study the notorious math –again.

October— It's raining and here I am, trapped inside the library, with my boyfried, and to study notorious math, again.

Originally: 
I’m stuck on a question with ugly numbers and sin, cos, tan… I just want to burn the whole thing down.

I’m stuck on a question, with ugly numbers and sin, cos, tan— I just want to burn the whole thing down.

Enjoyment (7/10)
It's not the type of story I'll really read since I'm a fan of heavy angst but it was okay and I enjoyed reading the thoughts of the girl. 

REVIEWER'S NOTE: Hope I'm not that mean, I just wanted to help you improve!