Remnants of ancient Japan. The culture of the warrior-aesthetes who governed Japan's provinces from the 12th to the 19th centuries is the subject of a colorful and wide-ranging exhibition at Washington's National Gallery.

THE black stallion and his armored rider charging toward the entrance of the National Gallery's East Building are not just a banner blowing in the wind. They are a dramatic symbol of the new show that has galloped into town: ``Japan: The Shaping of the Daimyo Culture 1185-1868.'' The gold, black, and red banner, which covers one wall of the East Building, shows a 14th-century mounted warrior, bearded and fierce, his tachi sword raised, his magnificent horse clad in scarlet trappings. He is one of the daimyo (Japanese feudal lords) who ruled over the provinces for the shoguns, or military leaders, for 700 years.

The highest-ranking members of the samurai class, the daimyo were ``warrior aesthetes,'' who practiced the ``dual way'' of martial arts and also cultural arts, as ``Daimyo,'' an accompanying film at the gallery, explains. This exhibit includes 450 vivid examples of how that daimyo culture irrevocably stamped Japanese life and society from the Middle Ages through the late 1800s.

According to National Gallery director J. Carter Brown, ``This is the first time an exhibition of this size and scale has ever been seen outside [Japan].'' The show, which will appear only in Washington, is a rare one. (The last major Japanese art exhibition in the United States was in 1953.) It was organized by the National Gallery of Art, the Agency for Cultural Affairs of Japan, and the Japan Foundation.

Like the earlier National Gallery blockbuster, ``Treasure Houses of Britain,'' this show seems to have engulfed the museum. In addition to the dazzling displays of Japanese national treasures - landscape and portrait painting, sculpture, armor, swords, saddles, scrolls, screens, lacquer, ceramics, robes, No theater masks, and tea utensils - there seems to be a whole daimyo multimedia festival going on.

Giant red, gold, and white banners with daimyo symbols hang over the East Building's Atrium, where a fragrant cedar-and-cypress teahouse has been built, surrounded by a Japanese garden with trees.

At the entrance to the show, a traditional Japanese No theater has been constructed for public performances in the opening weeks. ``Jidai-Geki: Images of the Daimyo Age in Japanese Cinema'' will include 25 feature films, among them Akira Kurosawa's ``Ran,'' and a series of documentary films on everything from swords to Zen Buddhism will be shown.

The daimyo show itself is a dramatic look at a culture greatly different from that of the US. There is the mysterious, compelling portrait of Minamoto Yoritomo, first shogun of Japan, who sits in his black robes like some great, brooding dark bird. Andr'e Malraux described it as ``the Mona Lisa of Japanese art.'' A hanging scroll on silk, it was done in the first quarter of the 13th century and is classified as a National Treasure.

Other items officially designated Important Cultural Properties and Important Art Objects are also included among the works of art in this exhibition, which boasts eight objects owned by the Japanese royal family. Attracting a lot of attention is a towering eight-foot Amida Buddha of the Western Paradise, gleaming with gilt lacquer and gold leaf. It was done by Taikei in 1201. Armor - frightening enough to stampede the enemy on sight - is also on view; consider the Rosei Gusoku armor of the late 16th century, so inky and dangerous it might have been Darth Vader's.

The daimyo culture combines the martial arts, or bu, with the peaceful or governing arts, bun, as exemplified in the haunting ``Dragons and Clouds'' screens, done in gold and gray by Kaiho Yusho in the late 16th and early 17th centuries.

Jumpei Kato, managing director of the Japan Foundation, noted at the press preview that this exhibition, following an earlier one in London, was especially significant, ``because, for our people - Japanese people - the Americans are more important than the British ... especially people in Washington. That's why we made every effort to make this exhibition, for people in Washington to be familiarized with the Japanese daimyo culture, and especially this aspect of Japanese daimyo culture, which represents the spirit of the warrior class, which may be interpreted as the central cultural element of Japanese art and culture.''

Mr. Brown noted that it was an American initiative to have the exhibition, made possible with Japanese cooperation. ``Why do we go to all this effort? Well, as a gallery of art, we believe very strongly in the power of art to illuminate the relationships between people with whom there are ... barriers of language and distance and culture.

``So I happen to feel very strongly myself the kind of purpose that can be served by an exhibition of this kind, in helping bridge this legendary `East is East, and West is West' dichotomy,'' Brown continued. ``There is certainly no nation more important to the United States at this moment in history than Japan.''

The daimyo show will run through Jan. 23, but will be closed Nov. 28 for necessary rotation of fragile objects.

Museum bonuses

Two colorful and ritualistic Japanese arts, that of No theater and of the traditional tea ceremony, are also being presented to the public in the daimyo show now at the National Gallery here.

A traditional wooden No stage with a peaked roof and pine tree mural has been built on the mezzanine of the gallery, where public performances are scheduled for Nov. 1, 3, and 5. On a typical night, Japanese master players from the Kanze School of No perform such dramas as ``Tsuchigumo'' (``The Ground Spider''). Sumptuous costumes, music, dancing, and poetic choruses are part of the stylized theater, which dates to the 14th century.

At the daily Japanese tea ceremonies, the public can watch a black-robed tea-master from the Yanunouchi School of Tea in Kyoto preside over the 15-minute sequence of intricate rituals and then sip the green tea and nibble the sweet cakes.