People are often precisely who you imagine them to be. Just think of Donald Trump. But sometimes, more rarely, they are not. What did I know of the writer Ian Buruma before I met him? Well, I knew that he was half Dutch and half British. I had read some of his books, which I’d admired for their meticulousness and intelligence – particularly the unnervingly prescient Murder in Amsterdam: The Death of Theo van Gogh and the Limits of Tolerance – without ever quite loving them, perhaps because, on the page, he gives so little of himself. I had also noticed that in the relatively short space of time since he succeeded Robert B Silvers as its editor last year, he had managed subtly to reinvigorate the New York Review of Books (some different viewpoints; many more female writers). A novelist friend told me that he is “a nice man”. The internet informed me that he is a “global thinker”. I guess I thought of him as clever, controlled and somewhat stolid in a way that I consider (wholly unfairly) to be rather Dutch.

But then I read his new memoir, and all this went out of the window. Oh my eyes. A Tokyo Romance recounts the picaresque adventures of the young Ian Buruma in Japan, where he lived from 1975 to 1981. On the plane, I opened it reluctantly, fearing it might just be a very grand version of a gap year book – and in fact, it does come with a whiff of this, its author writing first of how, in his early 20s, he longed to escape the “slightly dull surroundings” of his upper-middle-class childhood in The Hague, a world of garden sprinklers and bridge parties. No sooner has our hero arrived in Tokyo, however, than the whole thing sparks astonishingly to life. We’ll come back to the details, lurid or otherwise, but for now all you need to know is that Buruma’s high-level immersion in the country’s culture begins with him tottering around on takageta, a high-heeled version of the traditional Japanese wooden sandals, and ends with him playing a character called the Midnight Cowboy in a play by the underground director and actor Kara Juro. In between, there are visits to porn cinemas, a string of lovers of both sexes, an appearance in a Suntory whisky ad alongside the great Akira Kurosawa, and a non-star turn in a butoh show in which he appears on stage wearing only a scarlet jockstrap.

Have the staff of the New York Review of Books read about this jockstrap yet? And if so, is their editor the kind of man who may be teased about such a thing? I long to know, though it has to be said that Buruma – bald, bespectacled, quietly spoken, somewhat withholding – conforms entirely with my original impression of him; that (alas) the comical, gauche, innocently sexy young man of his memoir is nowhere to be seen. Where, I wonder, is this creature now? In the NYRB’s surprisingly chi-chi Greenwich Village offices, where we meet one damp January afternoon, it’s the first thing I ask him – wondering if he felt, when he was working on the book, that he was writing about another person altogether. But (again, alas) he doesn’t exactly take the bait. Where you or I might cringe at the difference between our two selves, hooting and clutching our heads in hammy amazement, he offers only a kind of mildly judicious interest, as if his book were more exercise than confession, a study in recollection rather than (as is usually the case with memoir) a determined pouring-out.

“Yes, and no,” he says, answering the question. “Yes, in that you can recognise yourself, and not always in the best light. I feel that most memories are embarrassing: you remember things that still make you wince, and you’re sort of glad some people are dead because at least they don’t remember. But there’s another side to this, which is that the only way to write this kind of book – it’s a bit like fiction – is to turn yourself into a character. That gives you a certain distance.” Necessity was perhaps the mother of this invention, for he kept no diary in the period covered by the book. “It all had to come out of my head. You have all these snippets and impressions, and you have to make them into a coherent story. It is partly out of your imagination. Of course, memory works that way anyway. You’re aways re-editing it subconsciously.”

He knew the deal, which was that even when his character got things right, he had to be seen to be getting them wrong: “I was aware that if you make other people into slightly comic figures, you have to make yourself into an even greater one. It’s like diaries: the best ones are not necessarily written by nice people, but by shits who are not shy about showing themselves to be shits. People like Alan Clark. Tina Brown is an example of someone who wants to come across in her diaries as a sort of agreeable person. But an exercise in making yourself look good is fatal.” This is not to say that he is the most important character in A Tokyo Romance. “I knew my time in Tokyo was an extraordinary experience,” he says. “In those days, so few westerners had been in that milieu. But I could never find the right form to write about it, until I suddenly realised that the way to do it was to use these two men [Kara Juro and Maro Akaji, the butoh master who put him in the jockstrap] who had been so important to me. That took the story away from being entirely solipsistic, and then the writing went very quickly.”

How did he alight on Japan as his destination, if not his destiny, all those years ago? As a young man, it was natural to him to turn away from Holland, which seemed somewhat provincial in contrast to the sophisticated world of his British mother’s Anglo-German-Jewish family, with whom he spent his holidays; his uncle, whom he adored, was the film director John Schlesinger. At university in Leyden, however, he chose to study Chinese, on the grounds that it sounded glamorous and he liked the food – though he was not a natural Sinologist. “I spent more time dancing with Chinese boys at the DOK club in Amsterdam than I did on classical Chinese,” he writes. “The sensual allure of ‘the east’ was more tangible on the DOK dancefloor than in the Analects of Confucius.”

But then two things happened. The first was that he saw the Truffaut movie Domicile Conjugal (Bed and Board), in which a young Parisian man falls for a beautiful but elusive Japanese woman called Kyoko (played by the model Hiroko), who appears in the film as a kind of hallucination. Buruma, missing the movie’s message somewhat, fell in love with Kyoko: “I wanted a Kyoko in my life, perhaps even more than one,” he writes. “How happy I would be in the land of Kyokos.” The second was that he saw a performance of Terayama Shuji’s avant-garde theatre group, Tenjo Sajiki, at the Mickery theatre in Amsterdam: a “deeply weird, largely unintelligible, perversely erotic, rather frightening and totally unforgettable experience”. In the clutch of its kimonoed ogres, naked girls and ventriloquists in chalky kabuki makeup, there seemed to be only one thing to do: soon after, he headed for Tokyo.

There, he enrolled at the Nihon University college of art, where he was to study cinema. Not that he did much studying. The lure of the city was too powerful. (Later, he would write film reviews and work as a photographer’s assistant.) The US film historian Donald Richie, a friend of an acquaintance of his uncle and one of a number of exiled gay western men with whom he hung around at first, warned him that he would never belong in Japan, that he would always be a gaijin (a foreigner), pale as tofu. What the country would give him, though, was freedom, the chance to make himself into anything he wanted. Buruma seems to have taken this to heart. Nothing was out of bounds, nothing seemed impossible – or even terribly difficult.

Drawn to butoh, for instance, he began ineptly training with Maro’s dancers, and took part in one of their shows, for which all he was required to do was stand in his scarlet jockstrap while a female dancer in a tiny silver bikini bottom would perform a dance around him, at the end of which he would catch her in his arms. Unfortunately, having duly struck his Charles Atlas pose, he lost his concentration at just the wrong moment, and dropped her on to the stage floor. Did this put him off? It did not. Before long, he was in another show. This time he had to impersonate Hitler, to the sound of Ravel’s Bolero, while wearing only a jockstrap (colour unknown) and white makeup. With its climax during which the troupe appeared with dried fish hanging off their bodies on the end of red cords, like intestines, this piece seems to have been a bit more of a success.

More bracing still was the world of Kara Juro. In 1978, Kara announced to his young gaijin friend that he’d written a new play: it involved a labyrinth, pork cutlets flying through the air, a drag queen, a dog god, a fight over a placenta and a trip to Narnia. Buruma looked blank at this, as well he might. Nevertheless, he accepted a part as Iwan the Gaijin “who might be a Russian but who claims to be the Midnight Cowboy” (everyone knew about his uncle). For this, he would be required to wear a leather stetson. He would also join the company on tour, travelling in their minibus. It wasn’t, perhaps, the happiest of experiences. On one occasion he forgot his lines completely. His greatest mistake, however, was to intercede in a fight between Kara and his wife, Ri – a chivalrous gesture that may, he speculates, have been born of some inner desire on his part to be seen for who he really was. “So you are just an ordinary gaijin after all!” shouted the outraged Kara at him, words he was never able to forget. Who knows, they may still have been ringing in his head when, some while later, he decided to leave Japan, fearing that if he stayed he would “catch a dose of gaijinitis”, a condition that would cause him to become obsessed with “the often imaginary slights that go with being pegged to one’s ethnicity”.

Buruma, who is now in his 60s, still favours cultural immersion, though these days drinking coffee in French cafes is about as racy as he gets on this score: “I find trying to blend in exciting.” But yes, the shameless confidence has gone, just like his youthful passion for Henry Miller. “You feel invulnerable when you’re young,” he says, slightly wonderingly. He still visits Japan regularly (his wife, Eri Hotta, is Japanese), and this has kept him from falling into another expatriate trap: “I’ve seen this over and over: when they become older, they [expats] become reactionary in their views, and this is because the country they left is no longer the same, and they’re strangers to it, and so they cling on to some old ideal. I’m never away for long enough to fall into that.” Nevertheless, the Japan he knew doesn’t really exist now. “That world [the Japanese avant garde] started in the 60s, just as it did in the west. It was a Japanese variation of something that was going on all over the world. But if you think about the novels of Murakami, his world is its exact opposite. It’s very solitary, very westernised.”

A Tokyo Romance seems, at first, to stand apart from Buruma’s other books (though for all its loucheness, there is again a sense, as one American reviewer noted, that he would rather drop you at the kerb than open a door to you, when it comes to his inner feelings). However, once you drag your eyes away from the stage girls peeing into plastic umbrellas, the sticky sex in lavatory stalls, the man known as the Human Pump, there is no getting away from the fact that it shares some of his longstanding preoccupations: with deracination, with the question of what may happen to societies that are not bound by a common culture. “That’s absolutely true,” he says. It’s a thread that brings us, neatly, to Murder in Amsterdam – a book that appeared to represent the high water mark of something when it was published in 2006, but now seems more like a horrible amuse bouche. “Yes. One interesting thing is that the man who became the face of Dutch anti-Muslim populism, Geert Wilders, is hardly in the book. I felt: this guy’s not going anywhere. I was completely wrong.”

What does Brexit look like to him? “It is the most shocking political event in my life. It was like a knife going through me. It’s very painful, and we haven’t even seen the worst consequences of it yet.” Did he see it coming? “No. I was much more worried Trump would get elected.” Our preoccupation with the last war, as revealed in films such as Dunkirk, is to him striking: “It seems to express a mood, and yet a lot of things that have happened recently have done so because the generation that is running the world has no memories of it. The world we grew up in was created by people who were terrified the war could happen again, and they tried to make sure it wouldn’t. Less nationalism, more cooperation. Now real fascist rhetoric is creeping back into the mainstream. The old taboos are fading because of lost memory.”

To what degree should the New York Review of Books (readership: 150,000) offer resistance to all this? “It’s always been sceptical, left of centre. It was one of the few publications to be against the Iraq war. We don’t need political reorientation. But we are living in the age of Trump, and that does give publications that believe in tolerance and democracy a responsibility. How you deal with it is, of course, a big question. Just ridiculing his vulgarity isn’t going to help anybody. But you do have to keep at it.” Not that this is a uniquely American problem. In his eyes, parts of the British media are failing a pretty important test right now. “The Spectator. It used to be libertarian, cheeky. Now it’s like the Daily Mail. The difference is, I suppose, that its old spirit came from superiority. Now it comes from resentment and disappointment. That was true in the 1930s of some people who were drawn to fascism. They were often second-rate, third-rate, novelists and intellectuals who felt no one was listening to them – and that has crept into the Spectator, that sourness, the idea that ‘the world has been taken away from us’.”

How did he get the job as editor? “Rea Hederman [its publisher] was having lunches with various people to see what could be done. I realised there was a possibility of me doing this, so I offered my services, and that was that.” He enjoys it: “Everyone is so bright and well read, I get to soak up their ideas. One thing that is very different from Bob’s day is that it was his baby [Silvers edited the NYRB for more than 50 years]; he was three times as old as everyone else, and an absolute monarch. I couldn’t possibly behave in that way. It would be absurd. So it’s more democratic.”

We talk for a while of what he has been reading: Cecil Beaton’s Diaries, Craig Brown’s book about Princess Margaret. “I’m not very high-minded,” he says. But he seems to be drifting off, distracted, perhaps, by the siren laughter of his young colleagues around the corner. Taking my leave, then, I head in the direction of my hotel in the clammy near-dark, trying with every stride to match up the two men I’ve met, one in real life, the other in the pages of one of the strangest, most hallucinatory books I’ve read in ages. But it’s impossible of course, like chasing two pigeons – and in the end, seeing a red lantern, I give up and stop for sushi.

A Tokyo Romance by Ian Buruma is published by Atlantic on 5 April (£16.99). To order a copy for £14.44 go to guardianbookshop.com or call 0330 333 6846