An elegant middle-aged man, in a spotless black jacket, came up to me, hand extended, to say hello, and I was startled. My neighbours in Japan tend to be formal and reticent; few of them are eager to take the initiative. And we were simply standing around an art gallery on Kitayama Street in northern Kyoto, 20 years ago, where a handful of us had gathered to see an exhibition of a friend’s pen-and-ink drawings. In the classical sumi-e style, they were deliberately sketchy and full of emptiness; the heart of the paintings was the negative space at their centre, which every viewer could fill in according to his whim or choice.

One of the blessings of a writer’s life is that so many people are keen to tell you their story. But in this case, the more the intriguing stranger shared – in a calm and fluent English – the less I could be sure of. He had been born, he soon began telling me, in Shanghai in the 1930s, and when he sailed out of the exploding city as a boy, it was to land in a Japan that was equally desperate and broken. In his late teens, he had fallen in love with the daughter of the chairman of one of the most celebrated companies in Japan and followed her all the way to New York City. But soon her sense of duty and her role claimed her again, and he had to leave Fifth Avenue, alone.

One of the blessings of a writer’s life is that so many people are keen to tell you their story.

Before much longer, he was on the West Coast, at art school, he said, just as the Summer of Love was coming to a climax. I didn’t know quite what to make of any of this – there was no mention of a family, a home where he lived now, anything resembling a job – but I wasn’t surprised when a common friend told me that Shinsuke was a classical archer: He carried himself with the straight-backed clarity of a traditional master.

Our conversation ended, and I didn’t see Shinsuke for many years. But when my wife and I got married, two years after that chance encounter in the art gallery, suddenly a huge, Rothko-worthy colour field painting – one enigmatic red square, one enigmatic black one – arrived on our doorstep. Shinsuke, whom I’d met just once, had heard of our union and wanted to honour it, and he did so with the most arresting wedding present we were to receive.

Many years on, the phone rang in our generally quiet apartment. “I do hope I’m not disturbing you,” said a deep voice, not quite Japanese, and not quite not, “but I am coming to Nara, and I wonder if you might have an hour free?” When I arrived at the station, Shinsuke was seated in a café, with a book, in a beret, looking every inch the artist in Paris that, I was now to learn, he had been for many years.

The beauty of a haiku is that it doesn’t have to spell much out.

We walked among the 1,200 wild deer who govern central Nara, about 45km south of Kyoto, and my new friend, always courteous and quiet, opened himself up again in a few bold, intimate strokes. He came from a samurai family, he said, and his father always took great pains not to show emotion. Even at his death, he’d told his son nothing. He himself, Shinsuke continued, had a deep interest in shamanism and would be happy to introduce me to an old female mystic who was a distant member of the imperial family. When we parted, he handed me a card that contained just his name and that of the small island outside Tokyo on which he lived – with, he said, a beautiful young woman he took strange pains to refer to as his ‘adopted daughter’.

In any other circumstance, I’d have been sceptical: The more savoury the details a writer hears, the more he’s likely to be on alert. Mystification is the opposite of real mystery. But my friends who knew Shinsuke well assured me that none of his story was false; like most Japanese people, especially of his refined background, he was not given to exaggeration or self-promotion.

More years passed, and I heard that my mysterious friend had been airlifted out of his island after what sounded like a heart attack. But he kept on, as he’d graciously requested my permission to do, sending me letters, written in a calligraphic hand that covered barely two suggestive sentences on each small rectangle of paper, as if this son of a samurai were eager not to make the same mistake as his self-enclosed father.

And then one day there came a call and a courteous apology: Shinsuke was back in Nara, this time with a young woman he was to introduce as his best friend’s daughter. But the woman called him her ‘guru’ and they looked far closer than any college girl and elderly honorary godfather might be expected to be. As we sat in a dark, near-silent restaurant – all partitions and soft lanterns – Shinsuke abruptly stood up and stole away.

When he came back, the bill was paid. “I just sold a painting,” he insisted, “and I want to give you something in return.” For what, I wondered? All he would say was that he’d read an old book of mine on Japan, twice, and wanted to repay the debt.

My years in Japan went on, and I learned a little more about a culture in which the truest sign of intimacy is not needing to say a thing. The beauty of a haiku is that it doesn’t have to spell much out.

Then I received a call again, and it was that confident but unpresuming voice, apologising for the disturbance.

“How are you?” I said.

“I’m dead,” Shinsuke replied.

He heard the pause at the other end and chuckled.

“I mean, I died last week. I stopped breathing; they thought I was gone. But then they pumped me full of drugs, and now I’m okay. Not myself; not in your world. I’m having some quite interesting visions.”

That didn’t give me much to say in return, but Shinsuke had always had the gift of carrying himself as if in a parallel universe.

“Take care,” I said, after we chatted for a while. “And please give me a call as soon as you’re out of the hospital.”

But the next call I got, one week later, reported that Shinsuke, apparently a well-known painter as renowned for his elegance as for his mastery of both Eastern and Western forms, was dead.

My friend, a human haiku, always told me just enough to remind me of all I didn’t and could never know.

Now, some years later, he whispers inside me as few of the Japanese among whom I’ve lived for almost 30 years ever do – in part because our every meeting came out of nowhere, except what seemed like the imagination; and in part because my friend, a human haiku, always told me just enough to remind me of all I didn’t and could never know. It took me a long time to realize that Shinsuke had given me the most startling post-wedding present I ever received: the living, seldom-seen heart of traditional Japan.

Pico Iyer is the author of 12 books, including most recently The Art of Stillness and The Man Within My Head.

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