Here's some language errors that I highlighted for you
Kindly forgive me if I left out some, misunderstood your intention or made a few mistakes myself. =)

Description
I never even said one word to that guy.
I see Park Misun as being the love of my life

Foreword
When your friends mention his name
If only you know he adores you too.

Chapter 1
but nobody had seen her
me and Sunny screamed in unison
I said as I pulled him off me
Every time I talked to him he mentions that one girl (still does, right?)
Okay that one hurts

Chapter 2
We never talked to each other
First, he came to talk to me.
Minho looked at our schedules then smiled at me.
Class starts in five minutes.
lead me to the classroom
I could have just told her
in front of Key
Why are you like depressed or something? 

Chapter 3
It took for me to tell you guys so I can actually realize it --> I actually have to tell you guys to realize it!
an angel and a devil/demon
my failed attempt at starting a small talk
But I am starving though

Chapter 4
She rented the old movie (you said so in the previous sentence)
starring at her
How's your status with you and Minho?
it's not like we get to spend twenty-four seven together  --> it's not like the seven of us get to spend twenty-four hours together
get this whole charade over with
it clicked in my slow naive head 

Chapter 5
but nobody wouldn't answer
I was about to hang up when I heard Misun's voice.
Was there anything you specifically wanted to talk about?
the blazer was long enough to keep the dress from looking too short (it can't keep the dress from being too short, just visually)
The dress has a collar that pops up (still does)
all the guys borrow a pair of alligator shoes each
black rectangular rimmed glasses
she stood there with her feet
her hands on her hips
Her chin was in the air --> She lifted her chin (it sounds more accurate this way, I think?)
while she looked straight into the camera
How many are there?
have a career in modeling
she started altering the camera
in front of the white screened
I was exceptional --> acceptable
None of my pictures were good
all week
just thinking about going there 

Chapter 6
pick up the menu
Kamhasamnida --> Kamsahamida (I know it's Korean, probably typing error eh?)
I started looking around the restaurant
There food here makes me so happy
must have been his driver
injuring his knee popped out of place from when a ball hit it to hard --> injuring his knee when a ball hitt it too hard and his knee popped out of place
He turned towards the road of modeling
it's the card kissing one 

Chapter 7
I have never been to Lotte World.
but all I felt was the bumpy plastic table
Our first place couples
everybody is else is freezing
had an answer to all my problems.
He seemed to have hesitated about something
had an opportunity to hang up instead of answering the phone though
He started stuttering
it shook it for me
The second place winners
a couple that could have been in their thirties in the third place
I think we should have switched prizes. 

Chapter 8
won the first place
It was the weekend and I was sitting on a bench
What happen to our referee?
drinking half of the water in the bottle
I was without a car
did a spit take with his water (huh?) --> spitted out water
How did you forget you don't have your car?
Just ask me what all I didn't yesterday!
But I hopped up out of bed
must have gained focus
he wants food or to spends the night over.
you like her this much and are still nervous
had always hated me 

Chapter 9
stuck in classes so much (just Math)
they intimidated me
I saw Key squeezing Jonghyun's arm
I hoped he liked the taste of his own meanie medicine
and he did this
I turned my back on them so I could eat my piece of chicken
I have no food idea (huh?)

Chapter 10
Can we go to Accessorize afterwards?
I'm mean I guess we became friends this year
I had a small flashback of what happened at the mall last week
Matter of fact, he started talking to me last week. (No?)
Just think about it.
I was going through the skirts
mother's touch never hurts
After I finished with my math homework, and finished researching on the topic for my rough draft essay
our conversation do get awkward
we will be looking at each other's faces the whole time 

Chapter 11
my mom's actions
rinsed the shampoo out of my hair
one of those fancy ones
I have never put on stockings before
applied a light layer of Lancome's BB Cream
from my the crown of my head
secured them in the back 

Chapter 12
Where are you taking me
got off his seat
the pocket I thought I put it
I have will have a special treat

Chapter 13
could have been with her
at least I don't thinks so
as we paused at a red light
leaned on me as we watched in awe
backstage where the dolphins
where the changing rooms were
ahead of me so
reason why she was so ahead was because

Chapter 14
don't think he noticed
my feet where about shoulder width apart 

Chapter 15
I couldn’t want to believe
would have moved to Seoul earlier
claws scratching at my heart
have a fight with my mom

Chapter 16
have to one chair
assignment reminds me of when
chuckle a little too
since we just reviewed it this morning
could have executed it
that's cool I guess
should have known 

Chapter 17
that were usually inside
what if she was kidnapped
must have snuck back
then ran away 

Oh, and get rid of your habit of adding 'also' at the end of the sentences, it usually comes before the verb. =)
And you tend to put 'of' in lots of slots where it should be 'have' =)