Chapter 1: Wow that was dramatic.... In a good way. To be honest, this seems to be a confession from a long running novel, rather than a oneshot. Don't get me wrong, it's a nice oneshot, but it felt overly dramatic for the prompt. It was nicely written and I like your writing style, but there were a few points that I'd like to point out.

First, you gave no physical character description, so we don't know what the characters look like. As for their personalities, Haeyoung seems dramatic, but Jimin... he has no personality. He seems like a nice guy, but that's it. We have nothing on him. Maybe it's because we don't know his personality or anything about him, I felt no connection between the characters. We only got to read about their first meeting. I would loved to read about their relationship now, so that I can see the emotional connections between the characters.

Also majority of the story is from Haeyoung's POV, but suddenly Jimin's popped up out of nowhere. It was random and confusing. Great, we know he likes her too, but it takes away from the story. Not only is it confusing, but it takes away from your dramatic cliff hanger. Haeyoung is so worried about getting rejected, but when we learn that Jimin likes her too it's like case closed. We don't need to read the confession because we already know he's going to say yes. I'd rather read about him randomly kissing her and accepting her confession, feeling the relief at the same time as Haeyoung.

Lastly, I couldn't understand who was speaking. You tried to give details on who was speaking, but because all the dialogue was in the same paragraph, it was confusing. I thought Jimin was confessing when it was Haeyoung. Also at the end I think Jimin was asking her why she was crying, but I thought Haeyoung was asking herself that because of the way it was written. The dialogue was confusing.

Overall, I liked the descriptions and details in the story. I also liked the drama, but I did feel it was too much for a oneshot confession. Drama would suit novels better. Anyways, I can't wait to read your next story. I think the next prompt, Royalty AU... I believe, might be a better match for your writing style based on this oneshot. I can't wait to read it.

Chapter 1: This was cute! It was funny when Haeyoung started to cry after Jimin also confessed. I did like that the story was short and sweet but I think that more time should have been spent introducing us to Haeyoung. With OCs it's important to have more character description since most fans don't have general knowledge of their personality and characteristics the way we do of idols. I also think that more could have been done to flesh out Jimin - is he in charge of facilities? Who is he? There's also no mention of their actual friendship other than that flashback, which would have been nice so the reader could feel more invested in the relationship. Overall, it was a cute and fluffy story which fits what you were going for! :)

Chapter 1: Ah, to be young and in love...this story reminded me that it could at the same time be the best feeling ever and the worst feeling ever. Best because of the person you like, worst because of the possibility of rejection and ruining a good friendship.
I like your writing because it didn't feel like anything was lacking. Almost everything was clear to the reader.
I enjoyed reading this story. Good job :)

Chapter 1: This is really nice :)

Chapter 1: This was nicely done :) You got most of the story elements just like heclgehog said below, so good job on that :)

One thing I noticed in the foreword though was the line "Three years ago today, she fell for him" which might have been some sort of typo?

Chapter 1: This was done so well. Like its so short word count wise yet it has back story, conflict, character development. Nice nice nice. Plus it was adorable, obviously! For such a short fast paced story with only a few scenes, you did well with description and setting. Even though you didn't show many physical attributes of the characters it didn't take anyway from the story too much. Just a quick sweet little one shot~

Chapter 1: Hmmmm...nice fic *gives thumbs-up*

Chapter 1: I don't read xOC fics, so this is a first, so-
Congrats? I guess, for being the first? X'D
Okay, sorry, forget I ever said any of that
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I can't help but to laugh when Haeyoung cried again after Jimin confessed that he likes her too. X'D It's so cute whenever a guy gets panicky when a girl suddenly starts crying out of nowhere.

I don't really have much to say, so, yeah-
This is a nice fic, me likey. :D

Chapter 1: I'm wondering why Jimin was the one to close the school at midnight. It's really hard to confess your feelings to someone. I think your story reached the level of some readers that are having a hard time. Sometimes it takes a little while to say something, other times it takes years. But some people wait years, and miss the opportunity completely. They may have given up their love for each other and would have never known what it would be like if they did tell each other their feelings.
Cute story! Good luck with your future stories! ^,-

Chapter 1: A cute story I enjoyed. My heart fluttered every time Jimin's name was written hahah.
I like your writing, though it could be a bit more describable when it came to addressing the characters instead of just using their names over and over again. But a cute and fluffy one-shot that made me smile and think of the time I once liked someone years back. I enjoyed this story of yours~~ xx