Yes, Ashura is indeed the main character ^^

I own the whole manga, myself. Now, let me 
clarify this. Ashura is, technically, neither 
male nor female, but a sexless being. When se 
lived before, se appeared as more male, and thus 
many refer to that as Ashura's "male" form. 
Whereas when se was reborn, se took on a more 
female appearance, adopting breasts (as seen in 
the last volume of the manga), as well as being 
referred to as the SISTER of Ten-oh, DAUGHTER of 
Sashi, suggesting more femininity. Se is also 
referred to as "kanojyo" and called "ojochan" by 
Kujaku, again suggesting femininity. Se tends ot 
lean more one way or the other in sexual 
distinctions, though is truly neither (or 
both..they never quite say if se is a 
hermaphrodite or just sexless). 

I hope this clears things up ^_^

-Misha-chan