TOKYO — Soviet Foreign Minister Andrei Gromyko arrived here Sunday night for a week-long conference with high-ranking Japanese leaders and Foreign Ministry officials.

Gromyko, making his first visit to Japan, told a group of Japanese and Soviet officials and newsmen at Haneda Airport that he hoped his talks would "improve Soviet-Japan relations and help relax international tensions."

Gromyko’s Russian Turboprop airliner touched down at Tokyo at 7 p.m. and was met by about 150 persons, including Russian and Iron Curtain embassy officials and Japanese Foreign Minister Etsusaburo Shiina and his wife.

Mrs. Gromyko accompanied her husband here.

Gromyko gave a five-minute speech in Russian at planeside, shook hands with beaming Red diplomats and accepted several bouquets from Russian youngsters before being whisked away in a Russian limousine to a Tokyo hotel.

About 100 Japanese police were assigned to the airport for Gromyko’s arrival, but spectators made no attempt to go beyond police lines. A small truck full of rightist demonstrators scattered leaflets in the airport area denouncing Gromyko as a "Red beast" before his arrival, but they didn’t get near the plane or the welcoming party.

While in Japan, Gromyko will confer twice with Shiina, and he is expected to meet once with Prime Minister Eisaku Sato and with Emperor Hirohito.

He also will make a two-day sightseeing tour of historic, scenic and industrial areas in Kyoto and Osaka with his wife, via the New Tokaido Line’s "bullet train.’’

The veteran Russian diplomat will attend the signing of a new Russo-Japan consular treaty in Tokyo, and is expected to discuss such topics here as the Vietnam war, nuclear proliferation, Japanese fishing rights in waters around the Kurile Islands, and the return of the northern Japanese islands occupied by Russia after the war.