"Examination hell" looked like doomsday for Kenichi Takeda. Twice, the 21- year-old failed the make-or-break national tests for entry to a Japanese university.

Today, Mr. Takeda is bound for a small liberal arts school in the United States, where he was admitted after studying English for a year at the Tokyo branch of the University of Nevada at Reno.Though his English is shaky, Mr. Takeda was accepted by Point Park

College in Pittsburgh as a transfer from UNR. He'll begin his studies there this summer.

"The best thing about the American college system is that they give you another chance. In Japan, everything depends on how you do in your entrance exams. If you fail there, you've pretty much failed in life. I may not achieve my goal in the United States, but at least I have a chance," said Mr. Takeda, an aspiring film director.

Schools like the University of Nevada are part of an American higher education boom in Japan. Thirty colleges have opened branches here since 1982, when Philadelphia's Temple University set up shop in Tokyo. Nine are starting classes around the country now.

The boom is the result, largely, of the restrictive entrance testing - the "examination hell" - which keeps huge numbers of young Japanese out of

college. Last year, 403,000 high school graduates who took the test were unable to gain admission and the pressure is growing as the second postwar baby boom generation peaks.

Another, but less influential, factor is increasing dissatisfaction among many Japanese youths with the system here as a result of their travels to the United States and greater exposure to American higher education. Ranking educators are worried that Japanese universities don't encourage enough creativity and flexibility.

Nearly 85,000 Japanese students are now studying abroad, of whom more than 58,000 are in the United States - triple the number of five years ago. For those who can't, or don't want to go overseas for four years, the burgeoning American branch colleges meet a need. Some students use the branches as a chance to get an American-style education without leaving home; others use them as stepping stones to schools in the United States.

Most of the students in the American schools are rejects from the Japanese system. This casts a dim light on the colleges in a society where only two or three universities are viewed as serious.

Some problems stem from the refusal of Japan's powerful Ministry of Education to recognize the branch institutions. According to Keisuke Isogai, a ministry official, no American school has applied for accreditation. "It may be that some of them have not fulfilled Japanese standards, but I don't know

because they haven't applied," he said.

At the Japan campus of Southern Illinois University, which opened two years ago, enrollment has dropped by two-thirds and the dropout rate has soared. Shincho, a popular weekly magazine, described the situation at SIU as ''disastrous."

Yukiko Tanaka, a spokeswoman for the SIU branch, which is located in the small city of Niigata on the Japan sea coast, said many students were not prepared for the rigorous demands of an American college. Ironically, while Japanese high schools and the university entrance exams are extremely strenuous, college life has a well-deserved reputation for what former Prime Minister Yasuhiro Nakasone called a "four-year vacation."

But, as Mr. Tanaka noted, many of the difficulties are caused by the fact that some of the American colleges are here primarily to make money - for themselves as well as for their Japanese business partners.

"Some of the new arrivals are here just to make a buck," according to William F. Sharp, dean of Temple University Japan. "They have financial problems on their main campuses and they lack the resources to mount a program like this."

According to Mr. Sharp, the ministry "tried to discourage" Temple from opening in 1982. "They're no longer hostile," he added, "But they're not friendly, either." On the other hand, he said, if the schools were accredited by the ministry, "we'd no longer be American colleges." He explained that, for instance, they'd be required to employ an 80 percent Japanese faculty and stock libraries with Japanese books.

Without official Japanese recognition, the U.S. Council on Postsecondary Accreditation in February adopted 37 "principles of good practice" intended to assure that overseas branches operate by the same standards as domestic colleges.

Some schools here appear mainly interested in filling seats, the result sometimes of pressure from Japanese partners to enroll maximum numbers, without consideration for whether the school has the capacity to teach them as promised.

Typically, most Japanese students spend at least a year studying English full time before taking any academic courses. But many of the schools attempt to inculcate them immediately with the differences between Japanese and American classroom behavior.

"We're trying to teach them to be individuals, to stand up and ask questions, to argue and debate with the teacher," said Frederick D. Kramer, president of Concordia College Japan. "We're after them all the time to speak out."