When Kurenai stood by Asuma, they both kept a respectable distance from one another. Never too close, never too far; never too warm, never too cold. It was a narrow path walked, flirting with boundaries without ever touching them, kept in balance by their friendship and strong sense of duty. Kurenai never felt her comfort threatened by him, which served her life's goals and purposes well.
It was easy to remember she was a kunoichi with Asuma.
When Kurenai stood by Kakashi, they kept a respectable distance from one another, but somehow he always found a way to cross the line. His body may have been far from her, but his words reached too close, too deep, too intimate. Sometimes his eye wasn't friendly without ever being terrorizing, and his smile felt like it was breaking some sort of rule. Kurenai found herself fighting for something each time they shared company—control, order, clarity… her breath. There were times she had a hard time recalling who she was with him, yet at the same time, afraid to think she had always known.
Because it was easy to remember she was a woman with Kakashi.
-owari
Authoress Notes
I actually am an Asuma/Kurenai fan, as I mentioned in my first "chapter". In fact, I was a strong, solid AsuKure fan for so long, that any other pairing with Kurenai didn't sit well with me at all.
...Now I'm a fan of Kurenai/Crack. Seriously, putting her with just about anyone will intrigue me in some dark, fashion. I've become hopeless. But Kakashi is tied with Asuma as my favorite pairings for her. ...Kakashi is just somehow more fun to write. Sorry Asuma.
Well, it took me about a year to work out the whole KakaKure thing in my head. While a drabble does not sufficiently argue the point, ultimately, my reasoning comes down to something like this one. So for those who are trying to understand the pairing, maybe this can help just a little.