From Scott Green's current AICN Anime installment:
My concept of "bookshelf manga" has never caught on, but that's not going to stop me from evangelizing it. Most manga is written as disposable entertainment, and doesn't transcend that. Even for a compelling title like Tsubasa: RESERVoir CHRoNiCLE or Fullmetal Alchemist, to name a couple of best sellers, are they really works you'll want to read five or ten years from now? Then, there are works that rise to the level of literature, the Dickensian serials of Naoki Urasawa, Osamu Tezuka's serious explorations like Ode to Kirihito or Town of Evening Calm.
Funny that I should have just been reading Theodore Sturgeon's Some of Your Blood, since it was Sturgeon who most memorably insisted that 90% of anything at all is mediocre. Most manga is written as disposable entertainment because most entertainment of any kind is disposable — the jolt you got out of it the first time isn't going to repeat itself. Or the jolt you got out of it as a younger person isn't going to be sustained as an adult, because your worldview has evolved past accepting something like that. When you have an exception, like Osamu Tezuka or Naoki Urasawa, you tend to cherish it simply because you don't often get something worth coming back to more than once in such a field.
Like Black Jack himself, performing surgery in the dark: taking something ephemeral and making something not-so-ephemeral out of it is a rare skill. Not everyone can do it. Not everyone can hone themselves to do it. Not everyone who tries to do it pulls it off. And not everyone who pulls it off gets noticed or has an impact. How those things last are sometimes accidents of history. They can fill a space — "hittin' 'em where they ain't" — and out of that create the sense of something truly new.
Now comes the hard part: How much of that can you do on purpose? I've debated this point with other people a lot. I don't think you can do a lot of it on purpose. Some of it is just doing the things that keep you in the right place at the right time; some of it is happy accidents. You can't really make a cultural phenomenon — there has to be something about them that is primed to catch fire all on its own. If you try to engineer that, people smell it. They shove their hands back into their pockets and walk on. The real originals are unfakeable.
And maybe it's because something is borne of ephemeral origins that makes it that much more unfakeable. I once saw a man blow a square bubble, a trick that involved a cluster of other bubbles and some cigarette smoke. It didn't last for more than a few seconds, but that was the charm of it all. That and knowing in a day or two he'd be in front of another audience somewhere, in Pittsburgh maybe, doing it all over again for people now lucky enough to see it for the first time.