
And we have liftoff.
Way back when info about Angel Beats first started to trickle down the pipe, people drew immediate comparisons to The Melancholy of Haruhi Suzumiya. Those turned out to mostly be premature, yet even now some still complain about how it rips off other shows. I generally compare it to Haibane Renmei, and sometimes, if I’m in a bad mood, to Bleach (though that one is really stretching it). Add in how it bears all the marks of your standard Key adaptation, and maybe all those accusations aren’t completely unfounded.
But I come neither to bury Angel Beats nor to praise it. Rather, I’d like to discuss a question that probably has no clear answer: What makes one anime “original,” where another is “derivative”? Give it enough thought and you could make just as many claims of plagiarism about any other show: Natsume Yuujinchou borrows much from Mushishi, as does Needless from Scryed, and Ergo Proxy from Serial Experiments Lain, and the aforementioned Haruhi from Daisy Miller of all things (not an anime, I know, but go with me).
Now, a fool might here conclude that there can be no originality in fiction if all works derive from those before it to such an extent as listed above, and he would be wrong. I dare anyone to seriously accuse Haibane Renmei or Ghost in the Shell of being knock offs, of being unoriginal. See what happens.

Care to say that again?
What, then, is originality? Does it even matter?
For the first question, most definitions of the word include some variation of “new,” or “fresh,” but that’s a bit too abstract for my purposes. Thinking about the above list, I’ve come up with a few more concrete ideas: difference in audience, difference in thematic elements, evolution of genre, and combination of genres. The second question will have to wait a bit.

Could this be anything but shoujo?
To begin with, audience. Mushishi and Natsume Yuujinchou follow similar stories in a similar fashion: An individual who can see and must deal with supernatural entities has episodic adventures. But they appeal to entirely separate audiences; the former is seinen, the latter shoujo. The author must tailor the story to fit the expectations and tastes of its particular audience, and therein emerges the originality. Both works explore isolation, but that theme manifests in subtly different ways. Mushishi’s Ginko must stay on the move lest he bring misfortune, leaving him with few friends. Natsume has the same worries, but he can only work to preempt what danger he attracts, whether through action or self-imposed isolation. And where Mushishi (the anime, at least, I haven’t read the manga) hardly deals with it, it forms the focus of several episodes in Natsume.
Then, theme. Lain and Ergo Proxy both deal with an average person discovering he or she is some artificial entity of great power in a mostly cyberpunk setting. Lain focuses on the interconnectedness of an internet-based society, and Ergo Proxy on societal structure and function in a post-apocalyptic wasteland. They’re both very abstract in how they tell their story, and they resemble each other in other ways, but this difference in central theme forces them to diverge. By tackling connectedness, Lain tells its story through esoteric references and obtuse dialogue. While Ergo Proxy has plenty of both of those too, its post-apocalyptic nature necessitates a more action-oriented approach. Their different themes mean different styles.

Now, tell me about your childhood.
Next, evolve. Any genre, it doesn’t matter which in particular, has its own conventions and standards. After a time these grow tired and cliched. And then the genre must evolve. Ghost in the Shell is one of the earliest incarnations of what some call post-cyberpunk. While it owes its existence to the likes of Neuromancer, it takes those same tropes and makes something new of them. The heroes work for the government, not against it; the world actually is a mostly decent place to live. It not only continues the genre, but advances it.
Now, combine. Haruhi (the show, not the character) is a lot of things to a lot of people, and I don’t aim to review it. But there is one thing it does that distinguishes it from its predecessors. I say one thing, but it’s more like several: It takes and combines multiple genres to where you couldn’t classify it if you wanted to. But unlike how Cowboy Bebop and Outlaw Star pioneered a new genre (the space western), Haruhi combines so many you can’t really say it’s started one of its own. It simply is, for better or worse. It cannot become a new genre because it has no genre, and so it defies our expectations.
Perhaps that could do for a definition: originality is a deliberate defiance of expectation. Deliberate there is a key word, I think, though I suppose originality could arise by accident.
Where does that leave Angel Beats? It’s a bit early to be sure, but I see it as a combining of genres. Not quite to the extent of Haruhi, but it has the epiphanic prison aspect of Haibane Renmei, only with a lot more action, in a Japanese high school setting. Though I can’t really see it as founding a new genre itself.

Careful what you say.
But does it matter?
Well, yes and no. To be fair, I have and do enjoy a swathe of stuff which have no original feature whatsoever. Mostly they fall under guilty pleasures, but I do still enjoy them. The anime I really enjoy and remember, though, those all are more original things; they stand out in my mind because they are different. And sometimes they even affect the guilty pleasures. Consider what Evangelion did to the mecha genre.
Being unoriginal hardly keeps a show from being good, nor are all original shows the best. But which are you more likely to remember, I wonder.