Title - 9/10
It's really simple but unique. I was wondering if it's an inanimated object coming to life and I was somewhat right about it. It does makes other curious just by looking at your story title.

Foreword - 6/10
The foreword is really straight to the point and when I first read it, I thought that it's fluff and Kai being tsundere. However, you've only mentioned about Kai and one of the ocs. You should also briefly introduced the other oc as well if she is important enough to be on your poster. And it will be a lot helpful to briefly introduce all the characters, be it major or minor, as the readers will tend to be confused with the different range of characters. I would like it better if there's pictures of those characters in the description as I would be able to imagine those scenes clearly with those pictures. For example, in the first chapter, you mentioned about Kai's brother, Jungmin. Since there isn't any image of him, I immediately associate him with SS501's Park Jungmin. I think the black haired girl is Hana while the light colored haired girl is Sull-Hee, am I right?

Plot -  12/15
This story is like an anime. A guy who could suddenly see and talk to thin air and everyone, who doesn't have that power, thought that he was crazy. But the snowflake does seemed useless for a servant. She couldn't even get him a glass of milk! It's quite common in fanfics (Especially the ones with "sad" tags) but you are able to write it rather uniquely  with him losing two loves. However, this story doesn't have a deep background, and the background itself is rather important. All I know f