DURING THE WEEK starting Tuesday, Kabuki fans will be expected to leave the Kennedy Center Opera House after seeing only two hours and 40 minutes of Japanese theater.

This is thought to be about all Americans can take. And we are only given that once every eight or nine years, when a troup from the Grand Kabuki of Japan makes an American tour.

In Japan, where the Kabuki theater has a matinee and an evening performance every day, the shows are five hours each, and devoted fans often bring a hamper of lunch, or scoot out of their seats during intermission to get a haircut or shoeshine in the theater building.

Kabuki, as the leading actor of this troupe, Ichikawa Ennosuke III, pointed out in a recent interview, is the only one of the three forms of Japanese classical theater that is supported by its public alone. The more austere Noh drama and the Bunraku puppet theater - both of which contributed to the music-drama, demon-animal mixture that became Kabuki in the 16th century - receive government help.

But the hardiness of the Kabuki audience is nothing compared to that of its actors. Ennosuke III is a superstar, but his training and schedule are required of anyone in the field, he said through an interpreter.

And they must begin so early that the typical Kabuki actor is born in a Kabuki trunk, as it were. Ennosuke III is the sixth generation in his blood line to become a Kabuki actor, he was regularly taken to watch Kabuki from the age of 2, and made his debut at 8 years.

But his son will not carry on the tradition. Because Ennosuke III is separated from his wife, the child was not intensely exposed to Kabuki, and now that he is 10, he's much too old to begin.

From his own debut at 8, Ennosuke often appeared in five-hour productions at night, after he had finished his full school day. Additional training in dance started when he was 8, and singing at 12.

"Once, when I was 15, I wanted to become a movie director," he said, when he asked if he had ever considered a different life. "But I soon forgot it."

From the age of 18, he was appearing in Kabuki regularly, although he was also taking a degree in Japanese culture.

Now, 38, he has performed "400 to 500 roles," he estimates. There are 30 Kabuki plays that only he does. In a month when he is working - he does matinees (11 a.m. to 4 p.m.) and evening performances (4:30 to 9:30 p.m.) seven days a week, and in many plays he does more than one role.

"On a busy day, I might do 12 or 13 roles," he said. "In one play I do seven different characters."

What type of role?

That's a question for a Western actor who exhausts himself doing seven two-hour performances a week. Ennosuke doesn't know how to answer it. Of course, he plays young princesses, warriors, monsters, crones, demons, animals and whatever else comes up.

"The complete actor has to be able to do all roles," he said. "It's no fun if there has to be another actor for a part I could do."

The two plays in which he will star here are "Kurozuka" and "Yoshitsune Senbon Zakura," chosen, said Ennosuke, "because they are classic, very representative, and the story lines are easy to follow."

So here goes:

"Kurozuka," a play that Ennosuke inherited the tradition of performing from his family, has Ennosuke as a white-haired old lady who is a man-eating demon on the side. Persuaded by a wandering priest that she can still follow the path of Buddha, she warns the priest and his friends not to peek into a certain room while she gathers firewood for their comfort. The minute she leaves they do what all characters in all legends all over the universe do - and the room turns out to be filled with half-eaten corpses. The old lady finds out they snooped and gets some kind of mad. She converts herself into a demon and tacks them, but their spiritual powers turn out to be strong as their ill-advised curiosity, and she loses and disappears.

"Yoshitsune Senbon Zakura" is somewhat more complicated, possibly because it is 10 hours long. However, only one scene, "Shi No Kiri," will be done here, and in a tamer version than it is done in Japan. At home, Ennosuke does part of it suspended by a cable over the heads of the audience, but technical difficulties prevent his doing this at the Kennedy Center.

Ennosuke plays three roles: a man named Tadanobu, a white fox impersonating Tadanobu, and a white fox. Okay? When he is being a fox, he does a special fox talk, done by speaking while holding the breath.

In the nine hours preceding this scene, a 12th-century general named Yoshitsune (played by Ennosuke's brother, Danshiro IV) has been given a magic drum that he entrusts, along with his girl friend, to his faithful retainer, Tadanobu.

Yoshitsune has been fleeing from his brother during the first nine hours, and when "Shi No Kiri" starts, he again runs into faithful old Tadanobu. Yoshitsune asks him where his girl friend is, but Tadanobu denies any knowledge of her, and Yoshitsune becomes furious.

Then the girl friend shows up. She has another Tadanobu in tow who she says turned up, in a stupor, every time she hit the magic drum. Turns out that this Tadanobu is really a white fox in disguise, so no wonder the other Tadanobu doesn't remember what happened earlier in the play.

The fox explains that he has been hanging around because the magic drum is made out of his parents. When the fox leaves, the drum won't work any more, because it misses its child, so when the fox comes back, Yoshitsune gives him the drum.

During the ensuing family reunion, between Fox and drum, the magic drum announces that a bunch of priests are on their way to attack Yoshitsune, who has been lamenting that his home life has been even worse than the fox family's. The fox then drives off the enemy, bows to Yoshitsune and his girl friend, clutches his parental drum and disappears above stage.

Ichikawa Ennosuke was born with the surname of Kinoshi, and given the name Seikiko. This makes him Kinoshi Seikiko in Japan, but he has been traveling here under a westernized reversal which makes him Seikiko Kinoshi. When he made his stage debut, he took the name Ichikawa Danko III, the Ichikawa denoting the school of Kabuki acting to which he belongs, and the Danko indicating, because of the "dan," that he was a child actor.

The first ancestor of his to be a Kabuki actor was Ichikawa Danshiro (1651-1717), who passed the Danshiro named down through the family, although many of its bearers also took other names. Danshiro II (1858-1922) also took the name of Ennosuke I, and that began to be passed down.

Ennosuke II (1868-1963) was the grandfather of the present Ennosuke. Because his grandson was such a terrific actor, Ennosuke gave him his name the year he died, living out his remaining life under the name of En'o L. Meanwhile, his son Ennosuke III's father, Danshiro III, also died, leaving his name to Ennosuke III's brother, now Danshiro IV, who will also appear here.

But as every Ennosuke fan knows, he also uses the name of Fujimi Kan'en, when he gives concert performances of classical dance. That's what he does when he has a day off from Kabuki.