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

she never believed in love and miracles, until she met this poor guy, Jang Hyunseung, who changed her materialistic personality and life

Foreword

she can continue to live in this biased world
made him fall in love
the richest guy in the whole of  Korea
his father already trusted and passed his whole career to Kikwang (a whole there sounds weird)
who has always been overprotected by her parents (all parents do protect their children, no?)
he is one of those typical playboys

Chapter 1

I’m the hottest girl in the whole of Korea.
Hyuna waited for her mother everyday
on the chair which she loved the most
That one day, she didn’t believe any miracles, or that her mother would come to pick her up anymore.
that one thing that will bring her happiness (for me, I don’t think that the word brings happiness, the love does)
What I’m doing now is to ensure that I survive inthis biased world, surelyeveryone will do the same if they’re in my shoes.

Chapter 2

Mr. Don asked everyone to gather (called is so Chinese, I’m one myself >_<)
Your facial expressions look fake, where else Hyuna’s look real.

Chapter 4

just like what she was requested
Hyuna dance in her seat (you use in for seats)
Hyunseung wavedback atme.
She admitted she was a who always wanted money. (was a , so she no longer only wants money, right?)

Chapter 5

She whipped out her phone and looked at her contacts.
She scroll down some more and saw her best friend’s.

Chapter 6

The girls just spent their time playing around
Hyuna bowed at Mrs. Jang gratefully.