Min SeoYun is someone who had known KyuJong since long before they debuted. When he became a trainee, KyuJong introduced her to the other members and they met quite often ever since. They even became close, like siblings. SeoYun loved them very much that all she wanted was for them to be happy. When something really big came up and broke them, SeoYun sacrificed her all, against the advice of the Winchester boys.

Eventually a Kyu x SeoYun fic.
Will have a bit of Supernatural things just to give SeoYun a background story. Don't skip them, though. They're important, too. 
The Supernatural part is a bit different from the series. As in Crowley lives.

DISCLAIMER
I do not know any of the members and how they think. I only make most of the things up based on the things I watched. I do not know the real story or how they reacted to it. I simply made this story for my own entertainment. I share this to the world just because why not. Another thing to note is that I am neither a doctor nor a health major. I did try my best to do some research, but there may be some error.