SOME expatriates find that living in Japan is painlessly easy. The food is good, the trains run on time, and if an employer provides a cost-of-living-allowance, even the notoriously high prices aren't so hard to take.
Thlang Sophana's adjustment was more challenging. After fleeing the epic brutalities of Pol Pot's rule in his native Cambodia, Mr. Sophana arrived here in 1980 at age 12, one of a meager number of refugees Japan agreed to accept in the wake of the Vietnam War.
After three months of orientation, Sophana was placed in a Japanese elementary school with students three or four years younger than he was. ''It was embarrassing,'' he recalls. ''I was so alone.''
A soft-spoken man who keeps the top button of his flannel shirt fastened, Sophana explains that this transition prompted him and his wife to begin tutoring five newly arrived Cambodian youths in late 1994. The newcomers have joined family members who fled Indochina and settled here. ''I had a hard time after coming to Japan,'' he says. ''I didn't want them to repeat the same experience.''
The free instruction that Sophana and Chieng Seng Tiakkhena are providing is common among Asian immigrants to Japan, says Michihiro Okuda, a sociologist at Tokyo's Rikkyo University who studies Asian integration. The couple is part of a tiny Cambodian enclave of some 20 people living in this bedroom community outside Tokyo.
Although they have received some support from Japanese friends and a group dedicated to helping refugees, Sophana and Ms. Tiakkhena say they are still short of funds to buy textbooks and need volunteers to help with the teaching.
The newcomers face a country only gradually climbing out of recession. The couple worries that unless the youths get high school diplomas, no Japanese companies will hire them. High school degrees are also necessary for the newcomers to become eligible for scholarships and support available to refugees and their families, according to the Association to Aid the Refugees (AAR), a private organization based in Tokyo.
Japan only reluctantly accepted Indochinese refugees in the first place. ''So far we have accepted only 7,000 refugees from Vietnam, despite geographical and cultural closeness - it's shameful,'' says Tadamasa Fukiura, director general of AAR. Japan has allowed 1,254 Cambodians, such as Sophana and Tiakkhena, to settle here since 1979.
As in Sophana's case, most found it difficult to adjust to a conformist society that does not gracefully tolerate difference. Sophana now describes himself as an ''ordinary salaryman'' who has made Japan his home, but says that despite his Japanese education and his 16 years here, he still feels only ''half'' Japanese.
But Professor Okuda says Japanese are becoming more receptive to their Asian neighbors. In the part of Tokyo called Ikebukuro, where Okuda focuses his research, ''Asians have endeavored to live carefully and to adjust to community rules,'' he says.
This striving, Okuda says, has relieved and impressed landlords and others, who have sometimes discriminated against non-Japanese. Illegal workers, many from China, the Philippines, Bangladesh, and other developing countries, have had a particularly difficult time since they began arriving in large numbers in the late 1980s.
The level of discrimination has often undermined Japanese attempts, on the part of diplomats and business people, to make the country a leader among Asian nations.
For the five young Cambodians, being in Japan is an improvement over life in their homeland, where a guerrilla insurgency persists and where a government elected in 1993 under United Nations auspices now shows signs of turning into a repressive regime run by erstwhile Communists.
''I think it's safer here than in Cambodia,'' says Em Chan Than, one of the students.
He and an older brother have rejoined their family after more than a decade's separation.
Chan Than says he aspires to go to university, even though there is little likelihood that his family will be able to finance higher education.
''In Cambodia,'' he says, ''only the father works, but here everybody does.'' Chan Than puts in a six-day week at a pickle factory and spends much of his free time studying. The other members of his family are similarly busy. ''We don't see each other much,'' he says.
But the life of a Cambodian immigrant in Japan is not all work and no play. At the end of an interview on a recent Saturday night - the only time that Sophana and Tiakkhena leave unscheduled - the group displayed pictures of a recent skating expedition the teachers had organized. Skating was a first for the newcomers, since Cambodian winters aren't exactly icy.
In parting, the Cambodians cheerfully uttered one of the most quintessential of Japanese expressions, which students say before exams and athletes before big games: Gambarimas - We will do our best.