TOKOYO’S SUMO DISTRICT : In the middle of Toyko, vistors can immerse themselves in the ancient Japanese art of sumo by watching wrestlers train, browsing in sumo gift shops and eating at sumo restaurants. Welcome to . . . : FAT CITY

Whomp! Grunt! Slap!

It’s 8 a.m. on a Friday. I am in a room with 10 men averaging more than 300 pounds each, their corpulent bodies covered with dirt and sweat as they crash andcollide. They are bone naked except for loincloths; their hair is covered with thick grease and pulled into topknots.

Smack! The room is dead silent except for heavy breathing and the slap of flesh. It is unadorned, except for a dirt ring. There is nothing to break the intensity here of man against man, pitting muscle and might in what adherents consider a sacred blend of sport, religion and art spanning more than 2,000 years.

I feel as if I have stumbled backward in time to some primitive village where tribal rites of initiation into manhood are being performed. In fact, I am in the middle of Tokyo, in a district called Ryogoku that is the center of Japan’s sumo world--a world that is drawing international attention for its glamour, novelty and breathtakingly brute athletics.

You won’t find the area listed in standard tour guides, but here you can watch the sumo wrestlers’ morning training, browse through sumo souvenir shops, eat lunch or dinner at a sumo specialty restaurant, visit the sumo museum at the National Sumo Stadium. You can even shop for king-sized jeans or the 13-inch-long Japanese thongs worn by Akebono, the native Ha waiian-American who recently became the first foreigner ever to win the crown of yokozuna , or grand champion. When the 23-year-old sumo king, whose given name is Chad Rowan, was awarded sumo’s top honor, it gave a kick to the sport’s growing profile in the United States.

Only a five-minute train ride from Akihabara, the electronics district, neighboring Ryogoku is a throwback to Japan’s timeless and feudalistic past. While Akihabara, whose clutter of consumer temples selling high-definition TVs, postage-stamp-size tape recorders and palm-sized computers represents Japan’s most futuristic face, Ryogoku offers a glimpse into a fascinating aspect of Japanese culture that has not changed appreciably over centuries.

The district itself is located in Tokyo’s older section, a down-home, working-class neighborhood of small homes, shops and factories crammed together in a 30-block area bounded by the Sumida River to the west, the Toei Asakusa subway line to the north and the Tozai subway line to the south. The main action, however, is centered in about a 10-block area radiating out from the Ryogoku train station.

The sumo wrestlers you see strolling there still live in male-only communal quarters. They still conform to a strict hierarchical system where junior wrestlers do most of the cooking and cleaning for the “stable,” or club. They still wear the kimono, chonmage (topknot) and thongs that evoke images of 17th-Century samurai.

If you actually want to see sumo, Ryogoku is the place to try buying tickets before each of the three tournaments staged annually in Tokyo during January, May and September. Tickets range from about $25 for the cheapest seat to $600 for a ringside seat on the same side of the stadium where the emperor sits.

But obtaining tickets has gotten tough since sumo mania took off here three years ago and turned the wrestlers into national heartthrobs. In particular, the emergence of two handsome, skilled and relatively buffed-out brothers, Takanohana (formerly Takahanada) and Wakahanada, drew scores of new female fans to sumo and kicked up a public storm of interest in what once was considered an arcane sport for old folks.

As a result, unless you’ve got connections with a sumo stable or a Japanese company with season tickets, you’re pretty much relegated to lining up in front of the Sumo National Stadium three days in advance for non-reserved tickets. Or you can show up at 5:30 a.m. the day of the tournament for a standing-room-only pass, or pay triple the face value from a scalper.

If you’re lucky, you may be able to get a same-day ticket during the first few days of the 15-day tournament by lining up at the stadium at 10 a.m. But you don’t have to actually see sumo to make a trip to Ryogoku well worth the time. The district offers a cultural snapshot of one of Japan’s oldest traditions, a truly different experience--and just a plain good old time.

A day in Ryogoku starts early, but you won’t regret the lost hours of sleep. For unknown to most outsiders, several of the district’s approximately 20 sumo stables allow visitors to watch their morning training for free.

The wrestlers themselves are up as early as 5:30 a.m. and in the ring knocking heads from about 6:30 to 9:30 a.m. Not quite as ambitious, I don’t make it to the Ryogoku train station off the Sobu Line on the eastern side of Tokyo until 7:45 a.m., where I meet Times researcher Chiaki Kitada. We’ve decided to visit the Azumazeki Stable, next to the Honjo Fire Station off Mitsume Road in the district’s northeast section (4-6-4 Higashi Komagata). It’s headed by the sumo world’s only foreign-born stable master, the former Jesse Kuhaulua of Hawaii. The jovial sumo pioneer was the first foreigner to win a tournament, and recruited sumo stars Akebono, Konishiki and other Hawaiians to the sport.

The stable’s sign in bold black calligraphy was penned by former Japanese Prime Minister Yasuhiro Nakasone. We enter the training room, a sparse but airy enclosure of blonde-wood walls surrounding a dirt ring. There before us, like ancient gladiators, are huge, heaving, male bodies, wrapped only in brown training belts. While two wrestlers face off in the ring, the others jog around them, do stretches, lift weights. Some of them shoot us inquiring looks. No wonder: We are the only women in the room.

The male energy is overwhelming. I feel slightly embarrassed and extremely conspicuous. Sumo is a man’s world, where women are not allowed even to step into the ring.

But the Japanese manager, Kokichi Karimata, is extremely friendly. He tells one of the junior wrestlers to get cushions for us to sit on. Then he sees me taking notes in English, and is intrigued.

“You’re writing in English? But you have a Japanese face. Did your grandparents know English? Do your parents speak Japanese?”

He turns to Akebono, the 462-pound sumo champion who towers over everyone else at 6 feet, 7 inches and is distinguished by his white belt.

“Hey,” the manager yells to the champ. “She came from California!”

Akebono strides into the ring. He takes on two other wrestlers alternatively, making short work of them, pushing them out of the ring in seconds with his trademark double-handed thrust. Sweat pours down his face; heat rises from his back. (In sumo, the objective is to propel one’s opponent out of the 15-foot ring or cause him to touch the ground with some part of the body other than the soles of his feet.)

Between matches, Akebono clowns around. He burps loudly, and laughs. He playfully spits water on a junior wrestler, who doesn’t flinch. After leading his fellow wrestlers in closing the practice with a ritualistic circling of the ring, he clambers downstairs to the basement dressing room, cranks up the rap music and starts bopping. Befitting his rank, Akebono is endlessly catered to, as junior wrestlers scurry to wipe his back, serve him water and retie his belt.

Not all sumo stables accommodate visitors. Your best bet may be to call before going down. Most sumo books, as well as the English-language Tokyo-based Sumo World magazine (which can be found at some hotels and most bookstores), list stables and their telephone numbers.

And do observe sumo etiquette when watching practice. According to Sumo World publisher Andy Adams, visitors should not use flash bulbs, talk or approach the wrestlers during practice. Always ask for permission before taking photos. And, in deference to the sport’s male tradition, women should wear pants and sit with legs folded under or to the side, never cross-legged.

From the Azumazeki Stable, take a cab back to your starting point of the Ryogoku train station. The main street in front of the station is called Ryogoku 3-Chome; it is marked in English and will lead you north to the stadium and south to the souvenir shops, temples and sumo restaurants.

Chances of actually seeing sumo wrestlers walking the streets are high, except during March, July and November, when they are staging tournaments and exhibitions in other parts of Japan. Particularly around the sumo stables, we often saw wrestlers in jogging suits doing chores or decked out in kimonos, their belongings wrapped in Japanese handkerchiefs called furoshiki .

The Sumo National Stadium, a domed structure of green and gold, is directly to the right and clearly visible from the station. At tournament time the stadium is decked with gaily colored banners announcing the wrestlers’ names. From 1 p.m. or so, the sumo fans begin to gather to watch the stars enter the stadium.

Women ranging from schoolgirls to grandmothers swoon over the men (“Oh, he’s really big!”) and shamelessly grab a behemoth’s arm to pose for pictures. You can too, if you’re gutsy. (But ask first.)

“Hey, sister!” A man sidles up to us.”Want to see sumo? Only 12,000 yen ($95). OK, I’ll make it 10,000 yen ($80). You came all the way down here, you might as well see sumo.”

He’s a scalper, and if you’re desperate to see sumo, this is one way to do it. The scalpers are easy to spot--scruffy looking characters, often with leather jackets and portable phones, lurking in front of the stadium. They don’t speak English, but Kitada suggests saying to them “sumo chiketto” (that’s ticket, with a Japanese pronunciation) and negotiating the rest with a calculator.

Despite the excitement in the air during tournaments, there is an advantage in going to Ryogoku off season. Then, you can see the Sumo Museum inside the stadium grounds for free (during tournaments, only those with tickets may enter). The museum is small, but has a revolving collection of sumo paraphernalia. When we went, the museum featured several exquisite Japanese brush paintings of sumo wrestlers, as well as photos of sumo ritual, including the grooming of the wrestlers’ topknots. The topknot, a spiritual symbol of sumo, is cut off when a wrestler retires from the sport in an emotional ritual that inevitably moves the athlete to tears.

Head back to Ryogoku station. By now, your stomach may be grumbling. It’s time to taste chankonabe , the specialty sumo stew. There are several chanko shops in Ryogoku; most, however, are open only for dinner. Many are run by former wrestlers who willsometimes sit down and reminisce about their glory days. Current wrestlers tend to eat their daily chanko in their stables, but you may find them dining in local yakiniku , or grilled beef, restaurants.

For lunchtime, there are two shops just off the main Ryogoku 3-Chome. Momotaro is just outside the station’s west exit to the left; the sign is in Japanese but the place is unmistakably marked with samples of food outside the entrance. The lunch sets are tasty and reasonably priced.

Chicken chanko, a simplified version of the real sumo dish, is an iron pot of chicken, mushrooms, spinach and tofu stew with rice, all for $6.50. Other sets include shrimp and tofu, beef bowl and fried vegetables.

For a real chanko experience, however, walk along Ryogoku 3-Chome two blocks south. Take a left on the small road between the Mori Pharmacy and a rice cracker shop. The fifth building down on the right side, discernible by the brown and blue sumo banners, is Tomoegata, a chanko shop owned by a former wrestler of that name.

The meals are not cheap--they range from $25 to $36 a head. But the ingredients are of the highest quality, including crab, clam, salmon, sardines, scallops, beef, chicken and vegetables, all cooked in a hot pot over a gas grill in the middle of your table.

And what’s a trip to Ryogoku without stocking up on sumo souvenirs? Head south on Ryogoku 3-Chome until you hit the main intersection of National Road No. 14. Make a quick stop at the Eikoin temple here, where sumo wrestlers pray for success. Then head east on the national road.

A few blocks down on the left side is the Hoshi no Ojisama gift shop, whose windows are filled with roly-poly sumo dolls in all sizes. They also sell T-shirts, piggy banks, lighters and ballpoint pens, and hand out free maps of Ryogoku, although they are in Japanese.

Another shop, Okadaya, where the wrestlers custom-order their thongs, is a few blocks further east on the national road at the intersection of Midori 1-chome (marked in English). Slipper-maker Koji Okada proudly displays Akebono’s 13-inch-long sandals (the biggest in the sumo world, retailing for $225) and explains how the wooden clogs, or geta , are made thicker than usual to support the wrestlers’ weight.

Dusk is falling as we make our final stop at the Tomioka Hachiman Shrine, a Shinto shrine of red pillars, brown wood and dozens of brilliantly lit paper lanterns. An $8 taxi ride away from the Okadaya intersection, the shrine houses an impressive stone monument dedicated to all of sumo’s grand champions; their names are engraved in perpetuity. Near the front of the shrine entrance are stones with the wrestlers’ hand- and footprints.

From its inception two millennia ago, sumo has been closely related to Shintoism, Japan’s animistic native religion. In the “Kojiki,” Japan’s oldest account of its mythical traditions and historical events, the first sumo champion, Nominosukune, was worshiped as a god. As we climb into the cab, the taxi driver is listening to the sumo broadcast on the radio. Barely able to contain himself, he blurts out the latest news. “Kotobeppu got hurt,” he breathlessly announces. Then, “Who do you like? Ah, Akebono? He’s big, isn’t he? Second biggest to Konishiki. Really huge. You saw Mitoizumi? Ah, he’s a round kid, isn’t he?”

We know we are in Ryogoku.

* GUIDEBOOK

Some More on Sumo

Getting there: Take the Japan Railways Yama- note Line to Akihabara Station; transfer to the yellow Sobu Line, Track No. 6, headed toward Chiba. Ryogoku is the second stop from Akihabara. Or take a taxi from anywhere in Tokyo to Ryogoku Station. From the station, it’s easiest to get to the stables by cab. The Azumazeki stable is a $5, less-than-five-minute taxi ride away.

Where to stay: If you’re set on staying in Ryogoku, The River Hotel (2-13-8 Ryogoku, Sumida-ku; from U.S. telephones 011-81-3-3634- 1711) is conveniently located kitty corner to the train station. Rates vary $54 single to $96 double, up to $137. The Ryogoku Pearl Hotel (1-2-24 Yokozuna, Sumida-ku; tel. 011-81-3-3626-3211) is one minute from the station. Rates begin at $60 for a single. In adjacent Asakusabashi, the Asakusabashi Business Hotel (1-11-9 Asakusabashi, Taito-ku; tel. 011-81-3-3865-4747) is three minutes from the Asakusabashi subway and train station. Rates $60 single to $105 double.

Most hotels will assist visitors in calling the Japan Sumo Assn. for information about tickets, but generally can’t help obtain them.

Where to eat: Tomoegata (Ryogoku 2-17-6, telephone locally 3632-5600), with set meals of chanko , sashimi and appetizers $9-$72. Yoshiba (Yokoami 2-14-5, tel. 3623-4485), converted from an actual sumo stable with the ring still in the restaurant’s center. A varied and reasonably priced menu, with chanko about $13, fish and other side dishes $10 or less. Tamaya (Ryogoku 3-21-6, tel. 3631-3844), a restaurant more than 80 years old specializing in noodles and tempura. For the homesick, Denny’s (corner of National Road No. 14 and Ryogoku 3-Chome, tel. 5624-1066).

For more information: Call or write the Japan National Tourist Organization, 624 S. Grand Ave., Suite 1611, Los Angeles 90017; (213) 623-1952.