In Japanese diplomacy, the normal technique for dealing with trouble is to emit a great cloud of vague and ambiguous terminology that is designed to obscure, not heighten, the confrontation with friends or foes.

This is definitely not the style adopted by Sunao Sonoda, the new foreign minister. For the past month since he has taken the job, he has been shooting from the hip with a stream of sharp, anti-American statements that have raised eyebrows all around this gossip-filled capital.

They have got him in trouble with influential politicians, some of whom are going public with their criticism of Sonoda, and there is speculation that he may not outlast the next Cabinet reshuffling.

When the American Japanologist Edwin O. Reischauer made his block-buster remarks about American ships carrying nuclear arms into Japanese ports, most of the government hunkered down waiting for the storm to pass, and it eventually did.

Not Sonoda. He told a legislative (Diet) committee that Reischauer's remarks amounted to "uncalled-for meddling by an American with big-power arrogance."

A few days later, Sonoda was asked what he thought of reports that the Reagan administration might reduce its financial support of some of the United Nations organizations.

"The United States should not carry on like a god unless it pays its dues," Sonoda declared.

More recently, he has acted as the lightning rod in criticizing American requests that Japan build up its military force more rapidly to help defend sea lanes in the Pacific Ocean.

Sonoda told reporters he could comprehend a request to "add the second floor to a one-story house, but it is out of the question if they ask us to build a 10-story building."

In Manila recently for a meeting with U.S. Secretary of State Alexander M. Haig Jr., Sonoda left fly with a blast against he communique issued in May when Prime Minister Zenko Suzuki met President Reagan in Washington. That communique contained the fateful word "alliance" to describe the U.S.-Japanese relationship, and its military connotations triggered a major upheaval when Suzuki got home that eventually led to the resignation of Sonoda's predecessor as foreign minister, Masayoshi Ito.

Sonoda told reporters that the communique "was not binding," in the same sense as treaties. A few hours later, after seeing press accounts of what he had said, he put out a demurrer insisting he was referring to communiques in general, not to the one in Washington. Later, back in Tokyo, he denied flatly ever making any remark communiques.

It was not the substance of those remarks that got Sonoda in trouble. A part of the Japanese press had been expressing similar views, and it is doubtful that Suzuki would seriously disagree with their contents.

It is moderately fashionable to be anti-American in Tokyo these days. The imposition of a de facto quota on automobile exports to the United States, the ramming of a Japanese merchant ship by an American submarine that quickly left the scene, the furor over nuclear weapons on U.S. ships in Japan's ports -- all of these have contributed to the mood.

But a Japanese foreign minister usually seeks above all else to minimize disputes with the United States, not inflame them, and he is being criticized not for being unfair but for suspected incompetency.

"When he made his first remarks in the Diet [parliament], we thought that he was only speaking his mind," said a member of the Liberal Democratic Party. "But since the comments [in Manila] on the communique, we think that he is just not a very competent foreign minister."

Such critism had been kept quietly within the ruling party until an influential member, former foreign minister Zentaro Kosaka, asked Prime Minister Suzuki recently to get Sonoda to "behave himself." According to an aide, Kosaka observed that recent U.S.-Japanese relations had not been smooth and said Sonoda's behavior was not the way to solve the problems. There is a "strong attitude" within the party that Sonoda's behavior has become a problem, the spokesman said.

Sonoda's motives in unleashing his remarks mystify onlookers. He has a reputation for being outspoken, but during a previous two-year tenure as foreign minister he was known neither as a hip-shooter nor as an anti-American.

"Friendly and cooperative relations with the U.S. founded upon the Japanese-U.S. security arrangements are the cornerstone of Japanese foreign policy," he said in one major policy address in 1979.

His critics within the party privately accuse Sonoda of playing to the press, which has been unusually critical of the latest round of American requests for a Japanese defense buildup. Those requests, the submarine incident and the nuclear weapons issue have aroused latent hostility toward Americans who try to push Japan into a tougher, anti-Soviet military posture.

Some, however, believe his remarks reflect a genuine personal pacifism and nationalism. He has never been a part of the Liberal Democrats' element favoring substantial defense forces and recently, while minister of health and welfare, argued against a stronger military commitment.

American diplomats have been irked and puzzled by Sonoda's remarks, but insist that in regular day-to-day meetings with Foreign Ministry officials they have encountered no hints of any basic changes in the U.S.-Japanese relationship. Those officials have on occasion offered explanations of his comments "and they have explained them satisfactorily," a U.S. Embassy spokesman said