Mr. and Mrs. Umeya Shokichi and Sun Yat-sen. From Umeya Shokichi Album, 1914, Collection of Ayano Kosaka, from the exhibition "Sun Yat-sen and Umeya Shokichi: China and Japan 100 Years Ago."

TOKYO - In Japan, the centenary of the Xinhai Revolution is being marked with a variety of events, many focusing on Sun Yat-sen and his relationship with Japan. It is estimated that Nakayama Sho, as he was known in Japan, made a dozen trips to and spent more than 10 years living and working there.

A commemorative exhibition, "Sun Yat-sen and Umeya Shokichi: China and Japan 100 years ago," ran this summer at the Tokyo National Museum.

Umeya a wealthy businessman and trailblazing film producer with a penchant for revolutionaries met Sun in his Hong Kong photo studio in 1895. Over the course of the following 30 years, Umeya was to become both a personal friend and a generous financial backer to Sun.

The exhibition featured 249 pieces, including photographs from the Tokyo National Museum and Nagasaki University collections, and historical documents and assorted memorabilia from the personal collection of Ayano Kosaka, great-granddaughter of Umeya. The layout was centered on period photographs, mostly snapped in Japan and China. Particularly popular were a series of Umeya's stereoscopic photographs, forerunners of modern 3-D image processing.

Scaled-down versions of the show had gone up at Shanghai's 2010 World Expo Japan Pavilion last summer and in Sun's hometown of Cuiheng this spring.

Throughout his life the usually flamboyant Umeya remained tightlipped about his relationship with Sun. Less reticent was Miyazaki Toten, a philosopher five years Sun's junior who was ideologically enamored of Pan-Asianism and facilitated for Sun the introductions that led to the foundation of the Revolutionary Alliance that would bring about the 1911 revolution.

"The decade leading up to the 1911 revolution was a golden time for Japan and China," said Joshua Fogel, a professor at Toronto's York University, who specializes in the history of Sino-Japanese relations. "There was a rich interchange of students, academics and ideas.

"Miyazaki and the other Japanese who adopted Sun saw him as an extraordinary man and a hero. And just as Sun was and still is regarded as the father of his country a sort of George Washington figure Miyazaki Toten saw himself as a General Lafayette, someone from a foreign country sharing the same goals, and coming to his aid in his time of need.

"Japanese Pan-Asianists were also anti-monarchists," Fogel said, "because they believed the two went together. And so they connected with other Asian revolutionaries who wanted to overthrow either monarchies or colonial regimes.

"But some who professed support for Sun and Pan-Asianism were in reality looking at an Asia guided, led or even colonized by Japan. Some were members of the Japanese government or would later become involved with the Japanese government. And that whole 'equal internationalist' approach that existed in Sun's circle an egalitarian sense of various countries in Asia rising up together to create something that looked like democracy or a more republican form of government in Japan, that idea was crushed when the military stepped in and seized power in the 1930s."

A century after the Xinhai Revolution, Japan is once again courting Sun Yat-sen. Former Prime Minister Yasuo Fukuda visited the "Sun Yat-sen and Umeya Shokichi" exhibition in Shanghai, and some 30,000 attended the show in Tokyo.

Japan's Sun Yat-sen Memorial Foundation, which manages the Sun Yat-sen Memorial Hall in Hyogo Prefecture, has been organizing public events for two years. It will hold an exhibition on Sun's time in Japan in November, publish a book, and plans a symposium on "The Chinese Revolution in Global History" at Kobe University in December. "Japan became a hub of Sun's revolution activities," a Foundation spokesman said, "and that has influenced the Japan-China relationship ever since."

It could be argued that relations between Asia's two largest economies have improved little and that dynamics have shifted greatly since Sun's time in Japan. But now, as then, Sun's voice is being heard.

Recently quoted in Japanese media is a passage from Sun's 1917 tract, 'The Vital Problem of China," which reads: "The relationship between China and Japan is one of common existence or extinction. Without Japan, there would be no China; without China, there would be no Japan Under the principle of Pan-Asianism, Japan and China can together develop the natural resources in the West of the Pacific."