CASTLE ROCK - Hiroyuki Okabe expected to encounter rock 'n' roll, pizza and the aftermath of the North America's most recent active volcano.

But Japanese classical poetry? Who would have guessed that Okabe would travel thousands of miles to this small town in the shadow of Mount St. Helens only to run headlong into an obscure piece of his own cultural past?

Certainly not Okabe, a Yokohama college student who is spending precious moments on the last day of his month-long cultural exchange here composing the final stanza of a renga poem that has traveled from student to student, host family to host family, in a tradition dating back to 12th-century Japan.

Castle Rock's unlikely guru of renga is Terri Lee Grell, a transplanted Californian who runs the town's weekly newspaper and writes poetry in her spare time.

The irony of this cross-cultural exchange - an American who has never been to Japan teaching Japanese about classical Japanese poetry - has been a source of great amusement to Okabe and the 11 other Japanese college students who ended up studying renga between trips with their host families to Mount Rainier, Bumbershoot and the Pacific Ocean.

"It's a big surprise," said Okabe, a 21-year-old business major. "It's very funny."

"I knew Americans are interested in today's Japanese," added Rika Sugie, a 20-year-old Kyoto native. "But I didn't know they are interested in classical Japanese."

Renga, or linked verse, bears some resemblance to a poetry chain letter in which more than one poet contributes stanzas, or links, to the final product. Japanese poets developed a system of elaborate rules that turned the art into a game of wit and creativity for the intellectual class.

The poet Basho, better known in the West for his haiku, popularized the kasen renga, which has 36 stanzas to represent the 36 immortal poets of Japan.

But the quest for more intricate and challenging rengas eventually drove all but the most disciplined followers away, according to Grell. By the end of World War II, the renga poem had fallen out of favor and haiku, which traces its origins to a single renga stanza, had become more popular.

For most Japanese today, renga is a concept left behind in a junior high classical literature class.

"I knew just the name of renga," said Sugie, who is majoring in English literature.

It was disgust with the contemporary U.S. literary scene, not a love of things Japanese, that turned Grell into a renga fan. A writer since age 15, she was fed up with the exclusionary nature of a literary community that gave carte blanche to a small group of poets simply because they belonged to the club of published authors.

"It's all about the name," said Grell, 32, who moved here with her husband and child in the spring of 1987 in search of a piece of rural America. "If so-and-so wrote it, it must be great. You see the same names in all the poetry journals."

In Grell's mind, renga is a proletarian revolution of sorts in which individual poets are taking control back from the editors and critics who have controlled the standards of greatness.

"I have become more and more focused on the idea of cooperation and distributing control," she said. "In the contemporary literary scene there is so much aloneness. There's so much expected of you to be alone and in pain."

Grell was tired of reading poems that forced readers to maneuver through layers and layers of deep psychoanalytical ramblings.

Renga offered an avenue for prose that was not only simple but collegial because it forced poets to work together. The renga begins when a poet contributes a hokku, or first stanza. Others link onto the renga following guidelines set by the original author.

"Renga is not that kind of competitive feeling. It's a free-for-all with everybody competing," she said.

Less than a year ago, Grell took over a tiny quarterly magazine devoted to renga, which she renamed Lynx to represent the linked style and also the endangered status of this kind of poetry.

In a matter of months, Lynx has grown from 50 to 300 contributors representing poets from the United States, Greece, New Guinea, Germany, England, Czechoslovakia and South Africa. Up to 25 poets have contributed to a single renga poem.

Grell knows at least three other Japanese poets actively involved in renga poetry, although the renga revival seems to have picked up more momentum outside Japan where the focus tends to be on cultural imports from the West.

Purists might cringe at the western interpretation of renga, which often takes great liberty with the original form. Traditional renga established strict syllable and line counts for each stanza and often required that certain stanzas refer to the seasons, moon or flowers.

Western-style renga uses the linked form but allows wild variations that have included a crossword puzzle renga and an elaborate pyramid renga created by a computer.

"I noticed the first thing the Japanese students think about is the syllables and then the creative process," she said. "We're different. We think about what we want to say and then try to fit it in. If wecan't, we don't want ot do it."

Grell believes the renga revival taking root here in this small southwestern Washington town is a healthy melding of Japanese and American culture, while remaining loyal to the ideals of its founders.

"When I'm teaching renga, I tell my students that there is a difference between Japanese traditional renga and what has now started out as western renga," she said.

"We're following in Basho's tradition. Basho said, learn the rules and then forget them."