So what do those people whose names are shown in the opening and ending titles of Japanese animation shows really do, and how is it different from their counterparts in the North American and European animation industries? I dunno. Here's some rambling about it anyway. This is the first in a series so stay tuned. (I have used only the masculine pronoun "he" to save space and reading time throughout the following, but there are many women who work in these positions as well.)

Original Creator (gensaku)

The original creator is the person who came up with the concept for the story originally. This may be the original manga creator, a novelist, game developer, playwright, author, oracle, prophet, or whoever can come up with an original idea. (Prophets and oracles might be ruled out here as they aren't particularly original. Then again TV writers aren't either.)

Director (Kantoku)

Storyboard.

The director is responsible for the overall look and feel of the show and is the leader of the production. (Well, this is the idea anyway ) The director determines what sort of show he wants to make and creates a set of storyboards, which are sequential drawings detailing the major scenes of the show, sort of a visual script. They have various information about dialogue, music, camera work, and such and serve as a basis for the animators to create their layouts, then their key drawings from. (Some director's storyboards are more comprehensible than others. Some sketch very rough and some put a lot of detail into the drawings. There is no set way of doing it other than that everyone uses similar paper forms to work on.)

Enshutsu

Often translated as animation director or technical director. Enshutsu is one of the most difficult and most important jobs in the Japanese animation industry. The enshutsu is between the director (kantoku) and the production staff. He is responsible for checking and supervising the show through the production, from initial story to the final released product, and in many cases, has almost total control over it. He checks the animation drawings as they are being done, sets up the scenes before they go to camera and supervises the sound and voice recordings and all the editing amongst many other jobs. The exact job and responsibilities vary from company to company, and from show to show as well. Sometimes the enshutsu ends up as the whipping boy for the director; sometimes he or she carries the show and the director sits back and watches. On larger productions there is sometimes more than one enshutsu and usually quite a few assistants. It is important to have a good knowledge of animation production as well as artistic talent to do the job and it usually takes four or more years in the industry before someone can do the job right.

Character Designer

As the title states, this person designs the characters for the show. Although this may appear to be a very creative and interesting job at first glance, it is a very demanding and difficult job as well. Some designers are given great freedom to design what they want to but more often they have to work within the constraints set by the directors, original creators, producers, sponsors or other parties. The character designer creates a settei or model pack which contains each of the characters and defines the costumes they wear and what they might carry. The character designer should provide as complete a model as possible for the animators to work from or it becomes easy to go off model and makes the job of the animation supervisor (see below) even harder.

    

Character Settei.

Animation Supervisor (Sakuga Kantoku)

The sakuga kantoku(or sakkan he is often called) is the person who supervises, checks and corrects the key animators drawings. The changes can be for many reasons but are most often to bring the characters "on model" - so that they fit the fixed character designs. The animation supervisor is often, but not always, the character designer as well and does many of the incidental character subcharacter designs. (The periodic cameo appearances of anime characters unrelated to the show itself in the in the background is often due to bored/weird/vengeful/insane animation supervisors.)

  
Original Key Drawings

  

Corrections.

Key Animators (genga)

The key animators, or gengamen (even though they might be women), work from the storyboards to create layouts. The layouts define the scene's size, camera frames and positions, where the characters and such are and what the backgrounds will be like.
After the layout is OK'ed the gengaman do the key drawings for the scene which are then sent to the directors and the animation supervisor for corrections. (See above.) The time sheet (exposure sheet or xsheet) is also done by the key animator and defines the movement and timing of the scene and breaks down everything by frame of film or video.
In the US, these jobs are often split between different staff members with one group drawing the storyboards, another doing the layouts (and yet others setting the poses sometimes) and others doing the key animation. There are 2 - 3 steps below keys and before cels in the US but only one in Japan - inbetweens.

Inbetweening (douga)

The inbetweeners use the key drawings as reference points and produce drawings that fit between the positions on the keys. This smooths out the movement and makes the animation look better. (The more inbetweens there are, the more fluid the movement becomes and the more expensive the animation becomes.) Inbetweening is a relatively non-creative job. It is more tracing than anything else. The hours are long and the key animators are wicked and cruel and make the inbetweeners scrub the floors with toothbrushes and kick them with spike-heeled animator boots (they have little Madoka and Pretty Samy stickers on them) and never let them go to the ball at the palace. The cruelest part of being an inbetweener is that they rarely get to work on anything they are fans of and what they do get to work on they burn out on quickly. (I know some animators and an enshutsu that you can send into convulsions by whispering "Ranma" in their ears.) After 2 or 3 years of grueling inbetweening, animators who can handle it are usually promoted to keys.

Foreign Subcontractors

There are many good subcontractors in Asia but production managers seem bound by the secret Production Manager's Oath to save money to the point where they have to use somebody awful before they break down and pay somebody good more to do it right. The drawings are done quickly - perhaps it is more accurate to say "pencil lines are put on the suggested number of pieces of paper in great haste" - and the inbetweens range from passable to spectacularly bad. (We always keep the "best" ones and stick them up where everyone can see.)
Cels are more of a problem because they are more expensive to retake and take more time to produce. Cels are also much easier to damage by scratching or tearing. When I was checking cels for BUBBLEGUM CRASH #3, we got a batch of cels from a Chinese subcontractor that had some oily substance on parts of them, often smudged by fingers. I tried water, benzene, film cleaner, glass cleaner and pretty much every other solvent I could find in the company and the only things which would dissolve the oily stuff were gasoline and ethanol. Sitting in a small poorly ventilated room for 4 hours cleaning hundreds of cels with ethanol is not a good way to start the day.
Later, I found out that many of the cels for that show (and others) were done by political prisoners at a prison near Beijing. I had this horrible image of people being whipped when I sent back retakes with nasty notes attached to them. I imagined an army officer, who would not be out of place in the Manchurian Candidate, sitting behind a cheap desk in a unpainted concrete room saying, "Prisoner 321, you have not completed the minimum 30 sheets per day so you will receive no rations today. You will produce 40 cels tomorrow or face the same punishment."
That was the last time I worked as a cel checker.

Weird Anime Company Anecdote #238 (collect 'em all)

I was working at a background company called Atelier BWCA and one of the painters was a young guy just out of high school. He had been at the company for a year or so and did passable work but he wasn't very bright. He was always asking the other staff members how to write kanji characters when he would write a fax and there were times when I had to teach them to him. This usually drew sighs from the older staff and comments about how useless the youth of Japan have become. He was a really nice guy and was fun to be around so they went out of their way to teach him things.
One day at the end of the summer there was a really violent thunderstorm and there were bright flashes of lightning and loud rolling thunder. The young guy said that he had never really seen lightning before so two of the older guys opened one of the windows a bit so they could see out and pointed every time they saw a lightning bolt. The young guy would squint and say, "Where? Where? I don't see it!" "It doesn't stand there like a stork, you idiot, just look for the flashes." This went on for 10 minutes or so until a stroke of lighting hit the TV antenna of the house right in front of them, flooding the background room with intense light and making everyone's hair stand on end. BOOM! The thunder went off at the same time and was so loud that it shook the tables and paint sloshed out of some of the open jars. One of the older guys asked, "Well, did you see THAT one?" "What? What? Where?" They threw him down the stairs.