When Japanese Prime Minister Noboru Takeshita arrives in Toronto for the seven-nation economic summit beginning Sunday, he will be basking in the glow of solid economic achievements during the past year - rising imports, low unemployment, and low inflation. Japan has achieved what its trade partners have long demanded: growth fueled by domestic demand, not exports. No one says there are no problems. But as Foreign Minister Sosuke Uno said recently, the atmosphere in Toronto will be far different from the Japan-bashing mood of the Venice economic summit last year.
``Personally I'm not the talkative type,'' Mr. Takeshita said before leaving Tokyo. ``But I am going to have to speak up on economic problems, particularly on the specifics of how Japan is to contribute to the world.''
Takeshita is quite aware that his colleagues, particularly President Reagan, will be asking Japan to substantially increase economic aid to the developing nations. The Japanese Cabinet has already approved a plan to provide $50 billion of official development assistance to the developing countries during the next five years - double the $25 billion in the past five years.
Japan can well afford to give more. But already its aid - over $10 billion during the current year - is the highest in the world.
Takeshita said he would speak up on aid to the least developed countries, as well as on improving the quality of Japan's assistance, increasing grants (as opposed to loans), and giving recipithe right to use loans in ventures as they see fit, rather than just with Japanese companies.
The prime minister warned against ``misguided nationalism'' in bilateral trade negotiations, such as the protracted beef and citrus talks with the United States.
There is already controversy in Japan about the aid issue, to say nothing of other countries. Most newspaper commentators here thought the $ 50 figure approved by the Cabinet was far too modest considering that Japan spends only about 0.30 percent of its gross national product on aid, compared to 0.35 percent as an average for the advanced industrialized democracies.
Takeshita will also face criticism over Japan's continuing large trade surpluses, especially with the US (nearly $60 billion). Still, the summit climate will be different than last year. Japan's imports of manufactured goods are higher than ever, and the newly industrializing Asian countries are the chief beneficiaries.
Explaining these things to his fellow leaders is better done in private talks than in the hoopla of communiqu'es. This is why Takeshita sets such store on personal contacts with his fellow leaders. He has visited every summit colleague before leaving for Toronto, and has apparently managed to convince them that despite a diffident public manner, he operates behind the scene like a shrewd and seasoned politician.
``Nakasone promised, but Takeshita delivers,'' said a West German official at the time of the prime minister's visit to Bonn and Munich last month.
The principal value of the summit to Japan, commentators here say, is that it gives Takeshita his only annual opportunity to be seen as a participant at the table of the advanced industrialized democracies. Japan is not a member of NATO, nor of the European Community.
Furthermore, compared with Ronald Reagan, Margaret Thatcher, or Fran,cois Mitterrand, Takeshita is a novice in summit leadership and diplomacy. He is not a novice in the fine art of human relations, however. The Toronto summit will help him highlight the diversity of Japan's partnerships while keeping the security link with Washington as the bedrock of his foreign policy.