Dark brown hair. Dark eyes. He's about half a head taller than Uotani and over a head taller than Akito. Uotani comes up to a little below his nose, Akito doesn't even reach the top of his shoulder. Uotani is 168.5cms. Akito is 163.8cms. Which makes Uotani 5'5" and Akito 5'3". I'm going to assume he's as much taller than Uotani, as she is than Akito, plus a centemeter or two. So I'm going to add 6.7. That would make Kureno 175.2cms tall. This makes him 5'7" and slightly taller than Ayame (175cm), shorter than Shigure (178). It makes him a lot shorter than the tallest one Hatori (who is 182cm - Which is still only 5'9"). So I'm going to make him that tall. About the same as Ayame, but shorter than Shigure and Hatori. I imagine he doesn't weigh much. The boy looks like a stick. If you don't believe me, peek at this page. http://www.furuba.it/galleryBW.asp Scroll down to chapter 50 and peek at those pics. He's the guy in most of them.
This is all based on a metric conversion I found on the net.
Now, bed. I have a lot of stuff to catch up on tomorrow, and I need to give my sister some attention as well.