The main character, as you may have figured out by now.  Setsuna is pretty much your average Sullen Teenage Boy, excepting the fact that he's the reincarnation of an angel and all.  He's extremely emotional and constantly chastising himself for various actions (mostly his love for Sara ^_^;). Setsuna also has trouble keeping his thoughts to himself--often he just says whatever pops into his mind, not bothering to stop and consider the consequences (which  make for some very cute moments in the manga ^_^;--and odd ones, too, such as when he's been knocked out and Kira tells him to say something and he says "I want to have sex." ^^;).  In keeping with his emotional personality, Setsuna also seems to have a fairly short fuse--when he gets mad, he gets violent, and he gets _really_ violent.  This is probably Alexiel's influence, and there's a defense mechanism for it--whenever Setsuna sees blood, (or smells it, even) he gets very weak and sleepy. ^^; There are a few times where Setsuna attempts to appear apathetic, but in his mind he seems to be constantly agonizing over something.  His other major attribute is that he's fairly protective and dependent on his friends (especially Sara ^_^;), which I think is very cute. ^^