The word is "hyoh-bahn."

It is the subject of much interest here in this city of 12 million people. Their eyes are focused this week on two outsiders, imported warriors from a foreign land.On their right, they see Mike Tyson, a young, muscular champion who has trampled the heavyweight division like Godzilla on roller skates.

On their left is Tony Tubbs, a nice, likeable guy whose baby-fat bulges suggest he recently trampled the buffet table Bob's Big Boy.

That brings us back to hyoh-bahn. Reputation. One man wants to keep his. The other wants to destroy his and start fresh.

The odds don't seem fair. Tyson is buoyed by a $10 million purse, a six-fight package deal struck with Home Box Office and a network of advisors, trainers and sparring partners.

Tubbs signs for a gross purse of $915,000, has his sister helping handle the finances and finishes the week with one sparring partner.

The flow is all going Tyson's way, and Tubbs knows he must win and win convincingly Sunday night (8 p.m. MST, HBO) if he is to be crowned the undisputed world heavyweight champion at the Tokyo Dome.

"I've got to hurt him," said Tubbs. "I've got too much to lose if the fight goes the full 12 rounds. Can I get the win on a decision? Mike Spinks, Frank Bruno are all set up for this guy. He is nine years younger than me. Do you think anyone wants to see a California boy by way of Ohio mess up those plans?"

The answers, in Tubbs' mind, are obvious. Tyson must go down. But can Tubbs put him away, and equally important, not get bashed in the face while trying?

Tyson, his 33-0 record and his reputation as one of the hardest hitters in heavyweight history is apparently not a major concern in Tubbs' camp. Trainer O'Dell Hadley says Tyson wouldn't be a Top 10 fighter if he had been around during Muhammad Ali and Joe Frazier's prime.

His fight plan is "take the fight to Tyson," which suggests one of two things: Either Tubbs pulls off one of the great upsets in heavyweight history, or Hadley is going to pull Tubbs off the canvas within the first couple of rounds.

Tubbs, 30, wants to stay in tight with Tyson, leaning on him constantly to keep Tyson's devastating left hook in check. If it becomes a plodding fight, don't ask for any refunds.

"I didn't come here to satisfy anybody," Hadley said. "I'm here to win. If I have to kick and spit at you, I will. As long as I walk off with the belt, fine. If I can make it a lousy fight and win, I will."

The predominant theme of Tyson's last fight against Larry Holmes in January was whether Holmes could turn back the clock and beat a man 17 years younger. The answer was no.

The prevailing theme for this fight remains Tubbs' weight. Every time you think a new angle crops up, somebody comes along and makes a couple of fat jokes about Tubbs.

It happened Friday night at an HBO screening, when the biographical profile on Tubbs included shots of sumo wrestlers and William "The Refrigerator" Perry. There was even a scale plotting Tubbs' weights throughout his 25-fight career, which has included 24 victories.