I would like to start off with this.
I've had this vest for about eight months now. The vest is still in near mint condition after being worn countless times to conventions and hanging out with friends/parties.
A lot of people who give this vest below 4-Stars complain about the size.
A couple of things to note for this;
- "style slim vest"
> Slim
Which means, knowing it's already from Korea, it's also considered slim. You were also warned with the description of the item.
"This brand, TheLees, is almost slim fit style." directly from the page of this vest.

Now, I don't tend to write reviews because of personal preference, but I felt the need to for this one. Just because skimming over some comments, my friend who was interested continued to ask me "But these people say...". (Even after he saw mine and even tried it on...)
Sorry, not everyone is right. Everyone has a different body type as well.

I weight roughly 138(ish) pounds. I'm around 5'10.
I got this in US-Small(Korean-M).
However, when I purchased this months ago, I was around 148 pounds and 5'9. And it still fits me fine. Except now, I'm able to tighten the belt in the back all the way. (So I would probably need an Extra-Small!)

People don't understand that slim, is more or less designer brand formed. If you go to Wal-Mart or Kohl's for example, they have standard clothing. That is NOT designer clothing.
Best way to explain;
- Designer ) ( shaped.
- Standard | | shaped.

I would, even after all these months recommend this vest. If you do not know what size you are, simply go to a tailor and ask to get your base measurements.

Oh, one more thing.
The material is fine. If you're concerned with the buttons (Which I've had NO issues with) just simply stitch over them to re-insure it being stable.