THE TRUE IDENTITY OF Lian Hearn was until recently one of the most closely guarded secrets of children’s literature. Who was the author of the bestselling novel Across the Nightingale Floor, an adventure set in medieval Japan about which readers from 8 to 80 became passionate in the space of a single chapter? Was it a man or a woman? Was the author Japanese or European? Where had this passionate, ferocious, magical tale of revenge and love sprung from? It has been snapped up by Universal Studios and is progressing to a cinema near you in the wake of Harry Potter. Yet for three years nobody knew who the author was. Eventually the word spread that Lian Hearn was Gillian Rubinstein, an English-born Australian writer of teenage fantasy. The rangy, white-haired, white-skinned woman sitting opposite me does not look remotely Japanese; only her extreme stillness and reserve suggests something that isn’t Western.

“Hearn is derived from ‘heron’, one of the key symbols in the books,” she says, though she was also thinking of Lafcadio Hearn, one of the earliest European popularisers of Japanese culture. It is this culture, both ancient and modern, that obsesses today’s teenagers to the extent that manga comics and anime films such as Miyazaki’s Spirited Away have become must-have tokens of intelligence and style. Not that this was in Hearn’s mind when she began the Tales of the Otori.

She became hooked on the Japanese aesthetic when she discovered Kurosawa movies. She had moved to Australia with her husband and the country was much more accessible geographically, although she didn’t visit until 1993.

“It felt very familiar,” she says. “Their way of living seemed completely natural. Even in the middle of the modern world there is something very ancient about it. I heard a boy’s voice in my head which I tried to tell myself was too different, too much from an alien culture, but I knew I had to break the rules.”

The voice was that of her hero, Takeo, who at 16 returns to his home among the Hidden to find everyone he knows has been slaughtered by the soldiers of the evil warlord Iida. Vowing vengeance, the boy is taken under the protection of another warlord, Shigeru, whose heir and champion he becomes: but he can assassinate Lord Iida only if he learns how to get across the specially constructed “nightingale floor”, made of squeaking wood, in his fortress.

The need to kill his mother’s murderer becomes still more urgent because Iida is going to marry, and murder, Kaede, the ravishing girl Takeo is madly in love with. Takeo has magic powers inherited through his father — such as being able to make himself invisible and possessing hearing more acute than that of a dog.

Gorgeously violent, complex and well written, the trilogy about Takeo’s struggle to become ruler of both his country and his destiny now has a fourth instalment, The Harsh Cry of the Heron, which tells the tragic story of what happens not just to the original lovers but to their children. Hearn has steeped herself so deeply in the culture of medieval Japan that when we see European traders through the eyes of her characters they, and their customs, come as a shock.

“There is lots of very raw emotion — revenge is hard-wired into people, like a craving for justice,” she says of Takeo and his enemies.

Hearn had a conventional upbringing that included education at Church of England boarding schools. Her father died when she was 14 — a “terrible loss to me and my sister, which probably made us more eccentric”. She loved acting, and at Oxford received her first encouragement — from her French tutor — that she might be good at writing. After a spell at the LSE as a research assistant, she married, then divorced, a research chemist, met her second husband, Tom, a journalist and publisher, and moved to Australia. She did not begin writing until 1986, when her youngest child started school. Space Demons sold 250,000 copies in Australia alone, but, she says drily: “Nobody noticed because it was children’s literature.”

Her three children (one of whom is also a novelist) helped her imagination to develop but she had no idea that anyone would be interested when she finished Across the Nightingale Floor. The pseudonym came about simply because she wanted to start again without being pigeonholed. “I wanted to write without any brakes on, without making any concession to the child reader,” she says.

Success has helped her to buy a house overlooking the sea and increased her confidence as a writer — but is clearly not central to her life in the same way as her writing. Her website, lianhearn.com, gives some idea of the multi-layered quality of her imagination, and of the worldwide admiration for her novels.

Hearn loathes novels such as Memoirs of a Geisha, and is “extremely careful” about not expropriating other cultures, which she says would be all too easy to do. Perhaps one reason why Tales of the Otori is so resonant is because of the myths she has invented; she deliberately avoided words such as “samurai” and “geisha”.

She clearly loves and reveres Japanese culture and its people. “They have had very bad press all over the world, but I find Japan fantastic — safe, clean, friendly, optimistic. Japan was never colonised; it’s one of the few Asian countries which met and fought the West on its own terms, which I think is why it has been so demonised.” Not, I suspect, by Hearn’s readers.

The Harsh Cry of the Heron is published by Macmillan, £16.99, offer £15.99 from 0870 1608080

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