I'll start off by saying that the first thing that caught my eye was the prettiness of the art; seriously, these characters are just so terribly adorable, I honestly feel like eating them right up. And then. we get to the plot, there's been a number of complaints that there's a whole lot of convoluted emotional bull in the story, and frankly, I beg to differ. Koma starts off as a completely delusional whacked out psycho, but it's a way of dealing with pain.
People deal with pain in different ways, and I've no idea about others, but I've had friends who are twins before, and they're like two halves of a whole, that's how close they are. Losing a twin would feel worse than losing a limb, it'll be like losing half of your soul, it's like being incomplete emotionally.
Another thing about what Kamo said, if you dress and act like someone long enough, you can understand what's in their heart. While that may sound completely bogus, it's been mentioned during relationship management talks I've been to, so it's legit. And yes, I believe Kamo has the right of it when he said Chikanari loves Ayashi. But then a person can love more than one other, (As Laurell K Hamilton taught me) and Kamo simply didn't realize that Chikanari loved him as well, loved him more.
Of course, if you're the type to believe in the One True Love (Boy, then you'll totally hate Laurell K Hamilton's books) this probably isn't for you. But I think it's a nice change after all the intense all-consuming soulmates-forever-after, and all the silly-cute BFFs (Boy Friends Forever), their relationship is not particularly perfect, but the flaws are real and it makes for an interesting plot.