Title and Description

I like your title. I can see that it's relevant to the story and although it was not the most original (feels kind of generic), it would still draw me in.

Your description is really interesting the way you've put it, beginning with "In which…" and I like that. However, I think the next two lines ("because I am sick of…" and "'I'm Myungsoo. You?' 'I'm yours.'") don't really work with it. It would have been better if you had left it without the second and third lines, in my opinion.

Chapter One

"There was¹ just going to be two classes in there;² the smarter class, and his class."

1. "Two' is more than one, so it should be 'were' instead of 'was.'

2. Incorrect semicolon use. I think a colon would work better here.

"Who in the right mind would answer a simple question like that?"

*Their.

"Myungsoo that¹ just got scolded for eating one too many candy²."

1. *Who.

2. *Candies.

I particularly liked the last part, "Yeah, he was childish but Howon still loved him. Of course Howon loves him. Okay fine, hopefully. No, really, Howon should love him." Made me laugh XD

Chapter Two

"What the hell was that disgusting llama face."

End it with a question mark. It is a question, isn't it?

"Yeah¹,  how not bias² was his mother exactly?"

1. No need for this.

2. Maybe change to 'unbiased.'

"Sungyeol was friendly, despite that eccentric behaviour of his, and he was on good terms with literally all his neighbors."

Eccentric usually means friendly (more often than not over friendly). Using despite here doesn't work. However, if you move the 'and' and put it before the 'despite,' it could work as some find the quality of being eccentric or over friendly to be rather annoying.

Chapter Three

"'Do you miss your yeollie?'"

Caps, even if it's a nickname.

"Howon walked away from Sungyeol after the¹ certin² incident, as he waited for Sungyeol to walk in front of him. He could no³ trust Sungyeol anymore, especially after that."

1. *A. 'Certain incident' is unspecific, therefore the preceding article should not be specific.

2. *Certain.

3. *Not.

Overall Comments

1. Too much explanation regarding why Sungyeol did something or what would happen if he did it. Narration is not meant to explain everything. Some things might need clarification but sometimes it's good to just leave it for the readers to use their common sense or just figure it out later on.

2. Too many changes in perspectives. Although you are narrating in third person, if you are delving into the thoughts of the characters, try to narrate more from one person's side of things. If you do feel like switching, be consistent. Stick with Myungsoo's thoughts for a while before switching back to Sungyeol if you want to, but don't just randomly switch every few pieces of dialogue, or worse, continually switching within the same paragraph.

3. From Chapter 2 and on, there is some random font changing, and it's a little irritating to read unless it signifies a different section, which, in this case, it doesn't.

Your story is humorous and made me laugh on multiple counts (Woohyun's aegyo XD). Truthfully, I might have made it seem like I didn't like it, but I thought it was rather well written overall. I'm just the type of reviewer who only points out things that were outstandingly good or irritatingly bad (or just incorrect), so I'd just like to clarify that I did enjoy your story. Your grammar is very good, a lovely thing for me (it literally hurts my head to read stories with grammar and spelling errors every few sentences), and the few you had here and there can be excused since they were very minor.

However, I feel the characters do not have enough depth. Perhaps invest more time into developing a background or a deeper personality for each character. 

✖ review by ninjagiya