"Kan-gei Mi-tsu-bi-shi Ku-rai-su-raa."

Two years ago, when Cliff Darnall began charting a pioneering Japanese-language course for this fall at Bloomington High School, that phrase was not something planned for his first lessons on the phonetic Japanese alphabet called katakana.

But here he was, on a recent autumn morning in the American heartland, effortlessly putting the simplified Japanese symbols on the blackboard. His 19 students set about copying the phrase, which means: "Welcome, Mitsubishi-Chrysler."

The decision this week by the two auto makers to locate a joint $500 million plant here mirrors a longstanding effort by Bloomington-Normal and a Japanese city to touch each other with special warmth and affection.

For 23 years, Bloomington-Normal and Asahikawa, a city of 350,000 on the Japanese island of Hokkaido, have exchanged high school students, found mutual pen pals and taken other steps to bridge the cultural, racial and geographic gulf separating their nations.

When the effort began in the early 1960s, no one knew that the twin cities of Bloomington and Normal in central Illinois would become the site for a venture that will bring scores of Japanese executives and their families here to live.

When the car manufacturers announced Monday that they will build and operate an advanced assembly plant here for subcompact cars, the decision had a special meaning in this community of 85,000.

Residents talk happily about annual tax revenues of $1.5 million, with 2,500 new auto-plant jobs and perhaps 9,000 other related new jobs.

Residents also have a tangible sense of adaptability to the arrival of the newcomers. Threads of Japanese life are woven into Bloomington-Normal's everyday fabric.

Just a few miles from fields of ripened corn west of town, where the new Diamond-Star Motors Corp. factory will rise, stands a small Japanese garden, sent as a gift of the people of Asahikawa.

It is named after Dr. Motoichi Moriyama, an Asahikawa father who for almost 20 years fostered the Sister Cities program. A small bronze plaque beside the garden hails his contributions to the life of Bloomington-Normal and the quest for friendship across oceans.

City fathers proudly mention that, in an Asahikawa park, stands a bell tower, the gift of citizens here.

Every year, under the Sister Cities program, two teen-agers from each community exchange places, spending a full year in the other's homeland. People here say this has been a great help in breaking down barriers to understanding.

Delegations from the cities have traded official visits, and this summer, after substantial advance planning, the student exchange program was expanded, sending squads of junior high schoolers for summertime visits.

Japanese-language courses have been offered for several years at adult education classes and at University High School in Normal.

So when Darnall returned home here years ago after living several years in Japan, and was hired as a mathematics teacher at Bloomington High, his plan to add Japanese to the curriculum of the 1,500-pupil school seemed assured of success. He had additional help in planning the course from his wife Hiroko, who is Japanese.

Interest is so intense that another class section may have to be formed, Darnall said.

Elsewhere in town, preparations are under way to establish a private school for the children of Diamond-Star's Japanese executives, who will run the plant's daily manufacturing operations when it opens, perhaps by late 1988. Dr. Dennis Kelly, director of the Lab schools at Illinois State University in Normal, heads that effort.

Kelly said that the academy may swell to 250 pupils when the factory is fully operational. The separate school for Japanese children is required because the Japanese education system is much more rigorous than U.S. public education.

"There has to be a separate school in order for the children to return to Japan and be competitive," Kelly said. "These students are going to have to stay on track."

He is being aided in the effort by the Japanese Consulate in Chicago.

Each generation here has its own perspective on what is common ground between Japanese and Americans and where surprises are to be found.

Scott Carnahan, 18, a Bloomington High senior, said that spending last year in Asahikawa showed him that the Japanese "are really great people, who didn't look at me as an American but simply as another person." He said he learned from them new, unimagined powers of concentration.

"When they do something, they do it right the first time," he said. "To me, the thing is that the Japanese people are teaching the Americans how to do it [make cars] right."

Hiromobu Mori, 16, the Japanese exchange student spending this year at Normal Community High School, said that the experience has shown him "the bigness of America. It's very different here. There is more space between houses, and there is Dairy Queen. I like Dairy Queen."

Kohui Ikuta, assistant general manager of the joint project, said that, from a business standpoint, Bloomington-Normal's interest in Japan had very little to do with the decision to locate here. More important, Ikuta said, were the community's excellent transportation network and its distance from the strong unionism of Detroit and other auto towns.