They're surprisingly easy to miss, these curious structures now lodged between neighborhood shops and apartment buildings all over Hawai'i.

But these Buddhist temples tell the story of Japanese immigrants torn between holding onto their culture and assimilating into a new one.

"There has always been tension from the beginning to build something Japanese or something that was American," said Michael Schuster, curator at the East-West Center Gallery. "Every one of these structures is a miracle, in my opinion ... They're really a testimony to the endurance of the community."

An exhibit showing the historical progression of these temples in Hawai'i — and its correlation to the social transformation of the Japanese-American community — opens Sunday at the East-West Center Gallery.

In about a 100-year span, more than 300 temples were built in various styles, with various materials. Only about 80 remain today. They are considered the oldest Japanese Buddhist temples in the United States.

"We want to show the roots of the Japanese culture unique to Hawai'i as associated with the Japanese Buddhist temples," said Lorraine Minatoishi Palumbo, guest curator of the exhibit and an architect who specializes in historic preservation. "Hopefully, people will recognize the temples' significance and come away with a deeper understanding of the diversity and the historical significance of these little-known structures."

Exhibit organizers hope that showcasing the architecture of these temples — and their importance to the history of the Islands — will trigger preservation and restoration efforts by the community. Already many temples are heavily deteriorated or on the brink of being torn down.

"As a Japanese-American," Palumbo said, "this subject lies very close to my heart."

As part of the exhibit, Palumbo will facilitate a symposium (see box) to address how communities can restore or preserve these pieces of Hawai'i history. The goal is to designate these temples as national historic landmarks and find funding to aid in their preservation.

"Communities have to come together to preserve these historic structures," Schuster said. "We want to help people find the necessary means to do this."

The architecture of these temples illustrates the changing lives of Japanese immigrants and how their culture endured and evolved over generations.

When Japanese immigrants arrived in Hawai'i in the late 19th century, they brought with them a strong religious base in Buddhism, evident in the sheer number of temples erected all over the Islands.

The design and construction of these temples changed over time, reflecting a shift in the economic, cultural, ideological and often political landscape in Hawai'i.

In the beginning, Buddhist temples were built in the style of plantation homes, with totan (corrugated metal) roofs and porch-style entrances. These structures were built from whatever materials the immigrants could find. They often used scraps from torn-down homes to build their temples.

When they did have money, Japanese immigrants constructed more traditional-style temples, with customary ornamentation and architectural design.

But as the community grew more accustomed to Western ways, temple designs changed. During the early 20th century, temples blended traditional Japanese and Western styles. A temple could have shoji doors and kumimono (decorative bracketing), accompanied by double-hung windows and rows of pews.

The Pearl City Hongwanji Mission is a classic example of this temple design, Palumbo said. While its exterior displays traditional Japanese styles, its interior resembles that of a Christian church, with pews instead of zabuton and an altar built at the front of a long nave.

The garden fronting the temple, though, is distinctly Hawai'i. Traditional temples would have gardens either behind or next to the building with walk paths running through them.

"This was really a transitioning time," said Palumbo, who earned a doctorate in architectural history from Waseda University in Japan.

Then in 1931, the design for Honpa Hongwanji Mission of Hawaii on Pali Highway was drafted, sparking one of the most unusual trends in Buddhist temple construction to date.

Yemyo Imamura, Honpa's bishop at the time, wanted the temple to reflect the universality of the religion. His idea was to incorporate elements that represent ancient Buddhist roots from Southeast Asia with both traditional Japanese and contemporary architecture styles.

The temple boasts elements directly from Hindu temples, with domes and tower-like shikaras. (Much of Hindu temple architecture is connected to astronomy and geometry.) It was also the first time a non-Japanese company designed and constructed a Buddhist temple in Hawai'i.

Other temples followed Honpa Hongwanji's example, including the Soto Mission of Hawaii in Nu'uanu and Jodo Mission of Hawaii in Makiki.

But after World War II, Buddhist temple design began to incorporate more contemporary elements, making them look more like modern-day Christian churches. (These temples were closed during the war.) There was an apparent move by the community, many of whom were interned, to blend rather than clash.

"This was a gung-ho period to be as American as they could possibly be," Palumbo said.

And while the exteriors of these temples were so eclectic, the interiors — in particular, the altar area — are strikingly similar. The golden altars, on raised wooden floors, are intricately carved and flanked with statues of Buddhas and bodhisattvahs.

"That's the one thing they all kept the same," Palumbo said.

In addition to photographs and floor plans of these temples, the exhibit will include various temple objects and implements such as kimono, statues and bon dance garb.

"We want the community to comprehend the whole scope," Palumbo said. "People don't realize they're part of this whole important fabric."

Reach Catherine E. Toth at ctoth@honoluluadvertiser.com.