Don't mind the rating of "boring". I thought that you could give more than one rating. Woops. But, I did find myself skimming over the story.
I don't think it's bad though. I thought it was very interersting and you didn't go too far with the Isaaru/Yuna pairing, because to me, any pairing involving Isaaru would have to be fairly slow, IMO.
I thought the story had a nice ambiance to it, and it sported some very nice lines, like Isaaru's last line.
Overall, I think you did a decent job.