I have to agree with pigeon and otr....
First off, the dialogue is....well, just as ortsft...otrsf...I'm just gonna keep calling you otr, okie dokie? Anyway, as otr said, pretty much every single sentence has at least one exclamation point. Most of them have two. I know mangas are all about intensity! And energy!! but I think it's a little too imposing. The dialogue, and the story, are also very cliche, no offense. The whole "young child with happy family is orphaned when said family is brutally killed, and he eventually turns into a powerful warrior because of it" shtick has been done to death. Now that would be okay, if the story was interesting, or the characters where intriguing, or even the setting was new and engaging. But as it is, it doesn't seem to be breaking any new ground. What have you added to that plot line that makes it special, or different?
And the names, as has already been covered, are already well-known, and sort of...you know...someone else's. I won't bother going into that too much, but I would highly recommend spending that extra five minutes making up a few character names that aren't so well known. It's not that hard, honest.
Also, the only part of this that is actually "manga" (so far) is the picture you use as a header...I know you're trying to hammer out the script first (which, as I said, is a little predictable and not all that inventive...again, no offense) but I'm kind of confused...is it the manga, or the the novel-in-manga-format that you're actually trying to do? If it's the latter, why not just, I don't know, write a novel? If it's the former, then why also call it a novel, when it seems to be just a script?
As an end note that really has nothing to do with critiquing your work, I am wondering if the picture you've used as your header is actually yours. I'm not accusing you of anything, don't get me wrong, but I've seen many aspiring novelists on the web use someone else's artwork to sort of "sell" their writing. If it is, indeed, going to someday be a real manga, maybe you could also show things like character designs in your posts? (You do have those, right? Since you're so adamant about making a script, you should be equally involved in the actual drawing of your characters, right?)
Anyway, there's my two cents. Mayhaps if you tweaked the story a bit, changed the character names, and used some decent grammar and a punctuation mark that wasn't an exclamation point, it could be an interesting read. As it is, though...well, no offense (again), but it isn't very interesting.