(bows) I made some corrections regarding language for you too. :)
Forgive me if I made a few mistakes myself, misunderstood your intention or left out anything.

I only did up to the original ending. C=

 

Foreword

Junhyung finally knows

 

Chapter 1

time to time
his head kept screaming
He wanted to wipe away her tears once again like he had always done.
He wanted to hug her and reassured her that everything’s going to be alright like he had always done.
But this time, it was the end.
This was how far they were going to have to go.
HyunA looked up at him
as they met hers
That question kept popping up
she calls a miracle but found nothing
HyunA looked down
She looked at him
Junhyung looked at the small fading figure
He wanted to reach out to her and pulled her back

 

Chapter 2

HyunA quickly hides behind a wall
Her mind took her back
Her mind replayed everything
She dropped to the floor
her right hand went over her chest
reaching then clutching
She pulled both her legs in and hugged them
drip then fall
Junhyung just looked blankly
he loves the most
Junhyung knocked the doors to the office of his company’s CEO. (A CEO himself does not have a door, neh? xD)
* A suggestion, should be CEO Hong, not Hong CEO
he continued eyeing the man

 

Chapter 3

HyunA dropped her bag down onto the floor (the floor is not hers)
to find no one was around
She had been questioning herself
She wanted to get it off her mind
she still had their couple ring
she had removed it
her whole life seemed to be breaking apart
She felt hurt, yet numb.
Junhyung just kept appearing in her mind
Her emotions were completely mixed up
looked around the little room in detailed
a bouquet of wilting roses (wilting, girl, rotting? Eww...)
She then slowly laid down on her bed

 

Chapter 4

It was too sudden for her
She wanted to scream, but she couldn’t find her voice

 

Chapter 5

she caught a cold (I usually don’t correct conversations since it might be the slang of characters’ talking, but this is obviously not.)
her stuffs (no, you just don’t add an ‘s’ to it)
she went closed her eyes to rest

 

Chapter 6

Her days went almost similar
She just practiced and practiced and practiced.
She wore herself out
washed up and headed to the practice room
Her eyes brightened up
HyunA turned around and smiled
She had been practicing
whatever that followed up
She kept dancing
but she felt better
her body couldn’t take it
she danced for almost 14 hours

 

Chapter 7

they meet again
they seeked comfort in each other’s eyes
are you here for Junhyung oppa? (another conversation part)
She then frowned

 

Chapter 8

Her tiredness was starting to go away.
she knew actually paid attention
Her eyes widened
returning a tighter hug back to him
he and she were here
Her heart kept aching while her mind kept asking why.
She kept blaming herself
she got to the nearest bench but every step she made, her body hurts, her head spun

 

Chapter 9

Junhyung held the door opened for her
He tried again.
 

Chapter 10

he opened the doors and looked into rooms after rooms (opened what?)
Her heart broke
her eyes turned watery
A part of her wanted to ask him
He called out and looked at her.
what does he wants (put this part in Italic as well, it’s a thought, right?)
He wanted to talk to her

 

Chapter 11

Jihyun walked over to her and touched her forehead
it hurts (put it in Italic, or change it into hurt)
HyunA chose the easier way out
you’re stressed with your solo comeback (another conversation)
she couldn’t be bothered

 

Chapter 12

She had seen many couples
secretly laughed at her
HyunA waited patiently
put up on displayed
with a fake on confused look
Her eyes widened
she became excited
let go of him

 

Chapter 13

what time it was – 11am
reads her phone (past tense)
He had the urge
he was being stopped
attempted to ease the pain

 

Chapter 14

reads the time
she just wanted to leave
She then placed her cell
he went into the lift
he had knocked
landing on hard on the floor

 

Chapter 15

looked up at the person who had knocked her down
Her eyes widened
she took a better look
it was all just a dream
hoping it wasn’t her
 

Chapter 16

Her eyes sparkle like they had never

 

Chapter 17

Junhyung’s voice kept replaying
where she was
She needed a quiet place – she just wanted to sit down
getting lost at wherever she was
Dongwoon’s face reddened
He let out an awkward laugh
She felt emptiness

 

Chapter 18

hoping it was inside
he looked at her searching the lift
HyunA’s eyes widened and brightened
looked at him in shocked
Junhyung had this wide grin
Junhyung’s eyes widened
she had just heard

 

Chapter 19

She finally gave in to her urge of eavesdropping. (gave in to)
Hara finally stopped fidgeting
their fans had left them
she was in right now
She had never expected him to ask.
hoping she didn’t sound like she was too serious, although she knew how serious her reason was
hoping it wasn’t a wrong mistake (mistakes are wrong)
HyunA’s eyes widened
hoping everything would just disappear
Junhyung and Hara were inside
She quickly stood up; brushed her shorts
She looked back at her phone (her phone’s in her hand, so why back?)

 

Chapter 20

she had never felt this way before
she just wanted to collapse
She looked at the phone again, but squatted on the floor.
placed it against her ear
She neatened her clothes and hair

 

Chapter 21

There were two almost similar Christmas trees
special occasions came up
but she decided she wanted to know
She couldn’t let Junhyung suffer
His eyes widened
unlocked his phone and checked on
He read the message
He repeated after her message.
Is there something serious going on?(Junhyung’s thought)

 

Chapter 22

she wasn’t able to sleep
her thoughts wandered to Junhyung and Hara’s conversation she had heard yesterday
she sure was late
he saw a cab and quickly got in. (you don’t sit on a taxi ;D)
She sent the message
A group of passers-by

 

Chapter 23

leaving her consciousness (I guess?)
he wasn’t willing to

 

Chapter 24

Jihyun's legs gave way
letting her cry on his shoulders
He asked, concerned
Doojoon sure did not want
where HyunA was
Junhyung finally stopped
Junhyung finally knew what that means.

 

Frequent Mistakes:
By the way, it’s is mostly used for present tense, change these into it was/it were, alright?
I spotted quite a number in all the chapters. ^_^

Stuffhas no s

Eyeswidened, ne? :)

You don’t open a message, read it.