SHIN KANEMARU, the leading back-room politician in Japan, moves to center stage next week when he makes a historic visit to North Korea. Mr. Kanemaru goes as head of the largest faction within the ruling Liberal Democratic Party, bearing promises of aid, apologies for past deeds, and hopes of mending ties with the other half of Korea.
A Japanese Foreign Ministry official will be by his side when Kanemaru arrives in Pyongyang on Monday for a five-day stay.
North Korea, which has so far rebuffed Japan's offers for official talks or diplomatic ties, welcomes the Kanemaru visit as part of its campaign to fix a worsening economy and find new nonsocialist friends, say Japanese officials. Last April, North Korean leader Kim Il Sung declared that his country will establish ``friendly relations with the capitalist countries which respect our sovereignty.''
This change of heart by one of the world's last Stalinist regimes came after its foreign trade fell 10 percent last year and the Soviet Union, a major ally, moved to set up formal ties with South Korea and to put its economic relations with North Korea on a hard-currency basis.
In July, a delegation from the Japan Socialist Party, which has kept close ties with the communist country, made a warm-up trip to North Korea. Makoto Tanabe, the party's vice-chairman, also happens to be very close to Kanemaru. North Korea expands ties
Japan is not alone in benefiting from North Korea's newfound efforts to break its isolation. Talks with South Korea and the United States have been notched up to more serious levels recently.
The prime ministers of the two Koreas met in Seoul this month, the first official contact in 45 years. And last May, North Korea made a gesture by returning the remains of five US servicemen killed in the Korean War.
For Japan, the return of two live Japanese fishermen would be an equally telling gesture. The two were captured in 1983 on charges of being spies. Kanemaru said he would not go to North Korea unless it was likely that the men would be released.
But he also says that Japan will not pay ransom. ``If I say that Japan will provide compensation [for the release of the two men], Shin Kanemaru will be regarded as a national traitor who buys the two men with money. I will not do this.''
Just the same, cash-short North Korea is demanding that Japan pay reparations for its 1910-1945 colonial occupation of the Korean Peninsula. Asian diplomats in Tokyo say Japan may promise $6 billion or $7 billion, more than enough to cover North Korea's outstanding foreign debt, estimated to be between $3 billion and $4.5 billion.
North Korea also wants an official apology for the occupation. The Japanese emperor gave two partial apologies to South Korea in 1984 and last May. Kanemaru says he will at least apologize on behalf of his political party, and may carry a letter with an official apology from Prime Minister Toshiki Kaifu. Trade relations break down barriers
North Korea's trade with Japan, generally done through third parties or secret channels, has been about $500 million a year, or about 10 percent of North Korea's total trade, and the largest with any noncommunist nation, according to the Japan External Trade Organization.
Japanese companies have been wary of more trade, in case North Korea decided that private debts should be written off as war reparations.
Japan hopes North Korea will agree to the setting up of private trade offices in capitals, a possible prelude to full relations. ``A liaison office is probable, but not as a government office,'' says Foreign Ministry spokesman Taizo Watanabe.
If official talks come out of this trip, Japan hopes to encourage North Korea to allow inspections of its nuclear reactor by the International Atomic Energy Agency. North Korea signed the Nuclear Non-Proliferation Treaty in 1985, but so far has not allowed inspections.