below will be notes and things that caught my attention while reading. the neat arranged review will be after that.

From what I understand from the poem in the foreword, he likes her, she sings like an angel and he wants to sing with her. So he is a musician as well.

The font is hard to read >.<

Long, straight, dark gold brown hair. Soft husky voice, low soft voice. Long wavy black haired girl. Hmm...

but why did she seem not to notice my presence?!

Whats with the exclaimation mark?

The unnie should be more protective and aware of Myungsoo instead of just approaching him like that no?

-Genre
I'll put this between friendship and romance, leaning a little bit more towards the romance side

-Plot
It's pretty common, and I've seen it some times before. The way you've written it made it different. You used a lot of adjectives and descriptions to describe everything possible. I thought that your writing was pretty. The plot seems like the summary of a starting of a story (if that makes sense).
I'm honestly curious about Byunghun's disappearance. (Byunghun is LJoe's real name right....? Not that it really mattters)

-Characters
They feel blank. All 4 of them. Myungsoo falls in love with Jiyeon, likes music and is passionate about it. Jiyeon cannot forget her previous love, makes friends with Myungsoo. Is Jiyeon a girl who cannot forget the past easily or a person who can move on easily? Because from my thinking, her being friends with him so easily means that she moves on easily but she still remembers Byunghun. Well, they were supposed to get married and all...How long were they dating until they decided to get married?
The sister isn't as supportive as I thought she would be. Maybe she is, maybe you didn't express it well, maybe I couldn't get it well.

-Overall
I would say this a pretty piece of writing. I love the lyrics though =D especially two very first lines =]
Not much emotions were felt. Just a pretty piece of writing.

Mark: B

Thank you for requesting another review =] lets improve together ^^