The state of Maryland acquired a Japanese sister last week -- the prefecture of Kanagawa, home of the Port of Yokohoma, two major-league baseball teams and the ancient capital of Kamakura.

"Do not seek association with big fish, but strengthen solidarity with fellow small fish," is one of Kazuji Nagasu's favorite sayings. The popular 61-year-old two-term governor of Kanagawa visited Maryland last week to do just that -- by signing a sister state agreement with Gov. Harry Hughes and touring the state he feels has most in common with his own.

Kanagawa, located immediately to the south of Tokyo, is hardly a small fish. Its population of about 7 million makes it the third largest among the 47 prefectures, ranking behind Toyko and Osaka.

Maryland, with 4.2 million persons, ranks 18th among states this side of the Pacific.

"I see many similarities between Maryland and Kanagawa," said Nagasu. "They are both next to a metropolitan area, they are about the same size, Maryland has the Port of Baltimore and Kanagawa has Yokohoma, and Kanagawa is a center of manufacturing as is Maryland.

"Both have an interest in baseball, too," said Nagasu. Kanagawa boasts the Lotte Orions, who came in first in the Pacific League last year, and the Taiyo Whales, who placed fourth in the Central League. Hughes mentioned that he also used to play baseball, as pitcher on a farm team for the New York Yankees.

The sister state agreement signed by the two governors said they will exchange research and study teams, technical experts, teachers, students and information on enviornmental issues, educaton, health, welfare, labor and business.

Marylanders pointed out their considerable economic ties with Japan. Nineteen Japanese firms are located in Maryland -- pronounced Merryrando in Japanese -- and the value of cargo passing through the Port of Baltimore to and from Japan runs about $1.5 billion annually. Those goods last year included 90,000 Datsuns and 80,000 Toyotas arriving and 4 million tons of coal bound for Japan.

Highlighting what they had in common, from trains to assisted housing to baseball, Hughes treated his Japanese visitors to a tour of Maryland that was whirlwind to the point of bordering on exhausting.

Pople in Baltimore, Annapolis, Columbia, College Park and spots along the way may have noticed an official-looking delegation of Japanese in dark business suits and matching ties, accompanied by three huge bodyguards and a police escort in what might otherwise be mistaken for an airport passenger bus.

Nagasu, a slight gentleman with ramrod posture and eyes that seemed always to be laughing, led the contingent of 13, including four reporters, for a four-day visit that began with Nagasu having to rush out early Monday morning in Annapolis to buy a suit for the welcoming ceremony because his luggage was temporarily lost. The visit ended with the signing of a sister state agreement and the presentation of 300 cherry trees by the Japanese.

Hughes planted one of those trees on the Statehouse lawn last Thursday and said he will distribute the rest to Baltimore City, various state parks and each of the 23 counties.

After welcomes and briefings and dinner at the Maryland Inn, the Japanese were bused to Baltimore at 7 o'clock the next morning for breakfast with Baltimore City Mayor William Schaefer, a slide show of Maryland industry, a tour of sibsidized housing, a quick jaunt through the Walters Art Gallery, lunch with the Baltimore business community as well as a look at the B & O Railway Museum, a house where Edgar Allen Poe lived and the birthplace of Babe Ruth -- by which time it was 6:30 a.m. back in Tokyo and some of the guests could no longer keep themselves from nodding off.

The Japanese were attentive tourists, however, listening patiently to a lecture on Oriental art, crowding carefully into the tiny living room of Thomas Marshall and his wife Mildred, who live in a subsidized apartment, and snapping photographs of moderate-income renovated housing in Baltimore's Old Town.

"But wouldn't these be weak in earthquakes?" prefectural assembly speaker Naomichi Iwamoto commented to Nagasu about the two-story brick row houses.

"Yes, but there are no earthquakes here," reminded Nagasu.

"You see, we could not renovate like this, because most of our buildings are wood rather than brick, and also because land is so expensive," said Etsuju Fujikake, secretary to the governor. "Land in Kamakura costs $3,000 per tsubo (about six square feet),"

In an Oriental gesture, the American hosts gave the Japanese mementos at each stop, including tote bags, ties, a baseball bat and assorted other souvenirs, while the Japanese distributed silk ties with a seagull motif -- the symbol of Kanagawa -- and key chains and seagull lapel pins.