The Japanese novelist Haruki Murakami is one of the most compellingly original voices in world literature. Born in Kyoto, in 1949, the son of a Japanese army veteran of the second world war, Murakami used to run a jazz bar before publishing a series of weird and wonderful novels whose commercial and critical success have earned him superstar status in his native land.

The English-speaking world has taken longer to catch up with him. His novels have been fitfully available in translation (just two are currently in print in Britain) and it was not until last year's publication of the epic The Wind-up Bird Chronicle - a surreal journey through the dark interior of a damaged marriage, set against the even darker backdrop of wartime atrocity - that American and British readers awoke to his talent. The Wind-up Bird received rave reviews on both sides of the Atlantic. You'll now struggle to get decent odds against his winning a Nobel prize at some point in the next century.

Murakami is, in many ways, the shape of 21st-century fiction to come. Using the narrative mechanisms of Hollywood noir, he explores, in a surreal way, the metaphysical anxieties of our age while retaining a mordant grasp of its mass-consumed realities. His fiction belongs to no genre but has the addictive fluency of the best genre fiction. He writes equally vividly about the mystery of personal identity as he does about a man buying trainers in a mall. His heroes are likeable, easy-going guys who ask for little more from life than to listen to jazz records and cook good pasta. Then the telephone rings, or a mysterious woman turns up, and the world turns upside down.

The Wind-Up Bird, with its virtuoso set pieces - a Japanese officer being flayed alive, a massacre of zoo animals - displayed Murakami's fictional imagination at its most extravagant. South of the Border is an altogether more intimate piece. It was originally published in Japan in 1992, two years before The Wind-Up Bird. Since Murakami's most recent book has been a non- fiction account of the Tokyo gas massacre, we shouldn't infer too much from this slim offering about which direction his fiction is taking.

Hajime, our latest fall guy, is a happily married Tokyo jazz club owner. His life is thrown into disarray by the reappearance of his childhood sweetheart, Shimamoto. Never go back, the saying goes, but Hajime has to go back to go forward. Although he knows little about her adult life and not so much as a kiss has passed between them, Hajime finds himself risking all for the love of this cool beauty who sips cocktails in his club.

The title neatly sums up the trademark duality of this novel. First, the irretrievable idyll of childhood, of the 12-year-old Hajime and Shimamoto listening to Nat King Cole's "South of the Border" on scratchy vinyl; second, the restless desire "to find a new place, grab hold of a new life" which Shimamoto distils in the central image of light-starved Siberian farmers walking to their deaths in search of a mystical land that lies "west of the sun".

Background exposition and description are pared down and characters are animated in a single image. Murakami introduces Shimamoto, a girl with a limp to whom the pre-pubescent Hajime is drawn, thus: "Some of the others in our class must have thought her cold and haughty. But I detected something else - something warm and fragile beneath the surface. Something very much like a child playing hide-and-seek, hidden deep within her, yet hoping to be found."

Murakami writes with authority about what, for other less gifted novelists, is the crushing ordinariness of late-20th-century life. There is a lot of sitting around in apartments, and Hajime spends much time talking to Shimamoto in his jazz bar, like the postmodern equivalents of Trevor Howard and Celia Johnson in their station buffet.

Contemporary American and English readers used to divorce rates of 40 per cent or higher might well find the emotional compromises that resolve this novel an unconvincing return to the moral world of Brief Encounter. But cultural differences are at play here. Until last year, when an unprecedented 200,000 Japanese marriages were dissolved, divorce still carried a social stigma in Japan, not wholly dissimilar from that constricting the passions of 1940s Britain, although with a more urbane tolerance of extramarital affairs.

Or is it simply that the 12-year-old Shimamoto is right when she says: "After a certain length of time has passed, things harden. Like cement in a bucket. And we can't go back any more." So the past, for Hajime, as he is forced to choose between two loves, becomes another haunted country which doesn't issue re-entry visas.