In Quiet Moments, Chapter 1
Trees had many uses. They provided shade, wood for various uses such as houses and pencils and making a fire, and enhanced the balance of nature.
In Hiei�s case, they were a training tool and place for resting when his body so required.
Trees, in Hiei�s point of view (not that anyone asked) were one of the few things that humans had going for them. The trees in the demon realm tended to be spindly and have branches that broke easily. Compared to them, the human trees were strong, firmly planted.
Everyone else thought he was a lunatic for living like some beggar out in the forest, but he didn�t care. He never had cared for others opinions�since ever.
Yukina was the only exception, so in reality, he couldn�t say that in absolute faith, either. Like it or not, he had softened some with the passing of his probation in the human realm. That�s why he liked trees so much. They certainly aged, but never changed, never moved.
Bah. He was becoming sentimental.