I have just returned from my second trip to Japan (I have family there) and once again, I've been amazed by those most impressive of peoples and their glittering, futuristic capital. Tokyo is the city of dog lovers where you won't see dog's mess on a pavement. Its high-density streets are bustling but you'll never be jostled, let alone find any litter. And it's the metropolis in which it is safe even for six-year-olds to go to school on their own.

But on my recent trip I discovered something even more remarkable. I was curious about the background to Japan's tiny Jewish community, so I did a little digging and learned about an astonishing episode of history.

We all know how cruel Japanese soldiers were to POWs during the Second World War, and how appallingly they treated the Chinese.

But less well known is the fact that - despite its alliance with Nazi Germany - Japan offered Jews a refuge from the Holocaust. Many thousands were rescued by a Japanese government which consistently resisted Nazi demands to implement anti-Jewish policies, much less to deport Jews to the concentration camps.

By the late 1930s a number of antisemitic German books had been translated into Japanese, but they found few readers and had no significant influence on the population. And in 1938 Prime Minister Fumimaro Konoe and his military council prohibited the expulsion of Japan's Jewish settlers - merchants and traders who had come mainly from Russia, Germany and Eastern Europe, and settled in the port city of Kobe, where they established both Ashkenazi and Sephardi synagogues.

At the outbreak of war, Jews attempting to flee eastwards from Nazi-occupied Poland and finding themselves blocked by the Soviet Union, were offered an unexpected escape route via then-neutral Lithuania.

The Japanese consul to Lithuania, Chiune Sugihara, saved some 6,000 Jews by giving them entry visas to Japan, enabling their passage via the trans-Siberian railway to Vladivostok, and from there by boat to Kobe. The Japanese government required that visas be issued only to those who had gone through official immigration procedures and had sufficient funds.

Most of the refugees didn't fulfill the criteria, but Sugihara knew they were in danger if they stayed behind, so he ignored his orders and granted the life-saving visas anyway.

Once in Japan they were given shelter, food and medicines. Many then received asylum visas for Canada, Australia and elsewhere, as well as immigration permits for Palestine.

In November 1941 the Japanese government decided to consolidate the Jewish refugees remaining under its control by transferring them to the Jewish ghetto in Shanghai, which was under Japanese occupation. Amongst those protected in the Shanghai ghetto were the staff and students of the Mir Yeshiva, the sole European yeshiva to survive the Holocaust. (With visas issued by Sugihara, its 400 or so members had fled from Lithuania to Japan in late 1940.)

As the war neared its end, Germany pressed the Japanese army to liquidate the 50,000-strong Shanghai ghetto, but it refused to do so. The safe haven survived intact and after the war the majority of Jews who had been in Japanese-controlled territories dispersed to various Western countries or else emigrated to Palestine. Others stayed in Japan, with some marrying natives and assimilating into mainstream society. So why did the Japanese, capable of such ruthlessness towards other groups, display a soft spot for its Jewish inhabitants?

It seems that many within the Japanese leadership harboured a longstanding respect for Jews, in particular for Jewish financial and commercial acumen. This originated with the historic treaty in 1854 between Japan and the United States, which opened trade links with the previously isolated Far East country and heralded the arrival of Jewish merchants in Japan's principal port cities of Yokohama, Kobe and Nagasaki.

The first, in 1861, was 21-year-old, American-born Alexander Marks, who set up businesses in Yokohama and went on to make a hefty fortune. (He later moved again, to Australia, from where he continued to trade with Japan and became its Honorary Consul for the Australian colonies.) Another arrival was Jewish-American businessman Raphael Schover, who set up the country's first foreignlanguage newspaper, the Japan Express.

But perhaps their highest esteem was reserved for New York banker Jacob Schiff, scion of an illustrious rabbinical family from Germany.

During the Russo-Japanese War of 1904-1905, he extended a $200 million loan to the Empire of Japan - the first major flotation of Japanese bonds on Wall Street - which provided half the funds needed for Japan's war effort. Why? Apart from sympathising with Japan's underdog status, Schiff regarded the loan as payback, on behalf of the Jewish people, for Russia's bloody pogroms. A well-financed Japan won the war. I love that story.

And so decades later, the Axis pact notwithstanding, the Japanese could not view the Jewish race as an enemy to be destroyed.

Japan was quick to recognise the formation of the State of Israel and establish diplomatic ties. Interest in Jewish culture and religion gradually grew in Japan, even within the Imperial family. The first synagogue in Tokyo was opened in 1953 with a formal celebration attended by Prince and Princess Mikasa. The city's present Beth David synagogue and community centre stands on the same site, in a sleek modern building dating from 2009.

There are about 1,000 Jews living in Japan today, the majority being ex-pats from around the world.

Tokyo has the larger of two communities; there is a smaller, Sephardi one in Kobe. I think it is fair to say that these Jewish communities enjoy more peace and security than their counterparts in just about any other part of the world.

And in Yaotsu, in central Japan, you can find the Chiune Sugihara Memorial Museum, dedicated to the consul who defied his superiors (an extraordinary act of insubordination in rigidly hierarchical Japanese culture) to save thousands of Jews about whom he knew little, except that they needed his help. In 1985, the year before his death, Yad Vashem named him a Righteous Among the Nations. The only Japanese national to receive the honour.