Even though I like to gaze upon anime and manga with an artistic and pretentious eye, one has to remember that this stuff is first and foremost is a business venture for some exec out there, and as a result these works get twisted to varying degrees to make them more marketable. One of the ways in which these works get twisted is in their length. Anime length is typically restricted to episode counts that are multiples of 13, and manga length strives on reader surveys and runs as long as it remains popular. Incidentally, this is why I don’t read manga that often, since too much of it is just so goddamn long.
Length is critical is to a story. Besides it being the factor that determines for how long you sit in front any given anime or flip through any given manga for, it helps set the pace for the story. Sometimes the pace is perfect for the amount of volumes/episodes a story runs, and sometimes it isn’t. What it all comes down to is that some story writers have very clear idea of how much time they have to cram stuff in, and others have no idea when they’ll be cut. This stringent control of length obviously effects the quality of the storytelling, regardless of whether or not the story is “good” or not.
For those who don’t know, anime runtime is typically bought in packages of 12 or 13 episodes known as cours. While this may not be as transparent in older, longer running shows (probably because the system was different back then) this system became very apparent in the 90s with shows typically running for 26 episodes, and now with shows typically running for 13. This can of course be really restrictive on writers if they, for instance, have a story better suited for 17 episodes, but have 26 episodes to work with; or have a story best suited for 17 episodes again, but this time they only have 13 episodes. Obviously the former situation is better, but such restrictions often result in episodes made purely to fill up time. If these are good, that’s all fine and dandy, but whether they’re bad or good still effects the pace at which the show moves. As for the latter situation, what often comes about are stories in which things aren’t adequately explained and the way in which they end oftentimes makes little sense.
Naturally, if one is a skillful writer it’s not an especially tall order to write a story meant to fit nicely into a set amount of time (I think Sunrise just does this by making up shit episode by episode and hoping it all makes sense.) but it’s not an easy thing to do. There’s also often times pressure from sponsors to keep things open-ended for a sequel, or to change certain plot points due to marketing issues. What seems to be the most prominent pattern coming around due to these imposed limits (and of course other things like the shifting of audiences’ tastes) is we get shows that focus more on characters and less on story, resulting in a show which is a set of 13 individual stories in which things are started and resolved in the space of each episode. Sometimes there will be a push for drama near the end in attempt to punctuate the series. Sometimes this works, sometimes it doesn’t, but either way it’s the easiest way to deal with things.
I can’t write as much on manga, since I don’t read it as much, but what I’ve noticed with most popular manga (ie shounen, shoujo) is that until a certain defined point there will be a nice, somewhat thought out story, but after that point things will meander, or further story arcs will simply not be as good. This is obviously a result of writers not knowing when they’ll be cut off, and when they do get cut off the ending is either abrupt or non existent. Like with anime, because of this and other reasons stories have shifted to be more character centric rather than story centric, so the way in which things end is less of an issue. However, manga does tend to run on for too long for my tastes, and the material invariably becomes stale.
Some anime have found ways around the cour system by telling part of the story within the 12-epsiode TV run, then finishing the rest with OVAs, and I can say with some certainty that there are a few manga titles that can end whenever they please. But besides that, I think anime and manga would really benefit if their run-times weren’t so strictly controlled. Often times it’s not too much of an issue, but there are a good amount of a titles out there in which length has had a negative effect on things. I dream of a day when such limits are lifted, but that will of course never happen.