Chapter 4: Minjung was being cool to shrug off Myungsoo when he tried to approach her to get to know her. Since she doesn't know him well, she's bound to be hostile towards him. It seems that she doesn't want anything to do with him. She's only concerned about her brother. That's one reason why she decided to enroll in the same school as him. This way, it'd be convenient for her to keep an eye on him. He is the only family that she has left. So, she takes it upon herself to look after him more. Knowing Myungsoo, he'd definitely come up with a different approach for getting close to her. If things are sped up, there'd be no point to the story. For a story to progress, it needs to go through developmental stages.

Hyunji is one strange character. For someone who's not used to having long hair, it does feel hot to him. It makes the head feel warm when it's covered by a sheet of hair. It'd be interesting to see more of him.

Chapter 4: "Soften" is a verb. Since you're using it as an adjective, it should be "soft." "Hurt" is already in past tense on its own, so conjugating it is not necessary.

Some mistakes:

Where did I heard it?
Correction: hear

I was about to ask his name but, walked away and went to my other classmate which i don't know him.
Correction: I was about to ask for his name, but he walked away and went to my other classmate whom I don't know.
* It sounds awkward with a subject missing after the conjunction (but) when there's supposed to be a comma before it.

Now I can a higher ranking to work.
Correction: Now I can have a higher ranking for work.

I went back inside and quickly took of my jacket.
Correction: off

No problem! No. You didn't mention that English isn't your first language. Though, that possibility did occur to me. Reading more English books can help you to improve your grammar. It's best to write the dialogue (the characters' speech) separately from the actual paragraphs. It looks messy with everything clumped together, which is hard on the eyes. I don't find it boring so far. It is important to create some scenes for the main characters so that we can get to know them from different angles and see different sides of them.

Chapter 3: Minjung is being overprotective to watch over Minhyun at all times. Since their parents aren't around, she must feel the need to look out for him a lot. At first impression, he seems cold-looking. Myungsoo's priceless facial expression at seeing Minjung shows that he feels a sense of familiarity as though he's seen someone similar on the school campus. It must be the peers' first time to see twins because of the way that they reacted when they noticed the resemblance between the two siblings. For her statement about her track record to be confirmed, she'd have to be able to prove it to them. She doesn't seem to give any indication of remember him as the guy that had bumped into her. Since she did walk off in a hurry after he'd apologized, she must've not taken a good look at him. That was unexpected coming from Myungsoo. He's being like a total fanboy in his mind thinking of Minhyun's sister. Later, he might be in for a shock when he finds out that Minjung isn't who he really thinks "he" is. Using people comes with a price because someone's bound to get hurt in the end.

The verb "raise" should be used instead of "rise" to refer to the motion of putting one's hand up in the air. In this one phrase, the verb should be "beat," not "bet." It doesn't sound right to use the phrase "capture his heart." That means Myungsoo is planning to make Minjung, who he thinks is a guy, fall for him. "Use him" or "get close to him" sounds accurate. It depends on how you intend to phrase it.

"Fraternal twins" is the correct term to refer to Minjung and Minhyun. Identical twins are two people of the same gender. Twins that are fraternal can be two of the same gender or of opposite genders, and they usually tend to not look exactly identical to each other. This is besides the point of the story, but I thought to point this out.

Chapter 2: Hyunji seems to be majorly infatuated with Myungsoo. Calling it love doesn't sound accurate since the feeling that he describes is just an attraction--regarding his appearance. Love is something that runs deep. He doesn't really know the guy and hasn't interacted with him. There's no closeness between them. Since he is a straight guy, it's unlikely that Myungsoo would fall for him. Plus, he already has his eye on one particular girl. His plan would backfire if Myungsoo manages to discover his true identity at some point.

Rumors tend to be false, so it's best to not believe them. As friends, they should know him better than that. The queenka must be desperate come suddenly come up to him like that. She seemed to be interested in him while he clearly isn't. What he's been trying to tell them all along is the truth. However, they don't seem to be convinced because of how the situation looks to them when they witnessed that sight of Suzy embracing him. Her beauty must've gotten them fooled. Myungsoo's got a point about looks being deceiving. Appearance is not what truly defines one's character.

It sounds like Myungsoo is talking about Minjung. She's the character that we know who has a twin.

Chapter 1: This is a little surprising in comparison to what I read about Minjung's character in the foreword. It turns out that her being a lesbian is just a cover to keep guys from approaching her when they're interested in her as a girl. She really is taking her role as the elder sister seriously by supporting and taking care of her younger twin brother. Going through such hardship after the loss of their parents has influenced her to become a strong, independent person. Minhyun must feel like he's being treated like a child in the way that she speaks to him, and it's as though he isn't being respected like an adult or a person who can be mature. That seems to be why he always gets upset afterwards whenever they quarrel. She needs to be considerate of his feelings and try to understand him.

After reading the foreword, I get the idea that the two main characters mentioned will be starting off the story. It is important that the OCs be bring into focus to give the story its beginning. The title of this fic does direct the readers' attention towards them.

This seems to be an interesting plot. I haven't seen a storyline like this one, so it must be original. It looks like they'd be going through a lot of change their characters' development for their ual preferences to be converted.

Chapter 3: I have a feeling that this story is going to make me cry later