IF A nation can be measured by its public holidays, Japan is civilised indeed; Greenery Day was a few weeks ago, and, later in the year, the Japanese can look forward to Culture Day and Respect For The Aged Day. Yet the rest of the world seems wilfully to misunderstand Japan, preferring to regard the national priorities as exceeding production targets and getting drunk in karaoke bars.

The Japanese tourist authorities run a simple but effective scheme to help shed cultural myths and dismantle preconceptions. Nearly 1,000 Japanese families offer a welcome to foreigners through the Home Visit System, which (stereotypically) works wonderfully efficiently. I phoned the day before I arrived in Hiroshima and was assigned an evening with Mr and Mrs Obara.

Along with my baggage, I arrived laden with misapprehensions. Hiroshima, I presumed, must surely be a study in civic tragedy, its 1 million citizens bearing the private scars of living in what was the world's first target for nuclear warfare. Yet as the shinkansen (bullet train) eases into the station, Hiroshima looks a picture of energetic utilitarianism, indistinguishable from a dozen other Japanese cities.

At the tourist office I was given a bewildering address in a northern suburb of Hiroshima, and a map which made some sense of it. Mr and Mrs Obara are an ordinary family, living in an ordinary flat a few miles from the hypocentre of the explosion; it is hard to avoid defining places in the city in terms of their relation to the bomb blast.

At 8.10 on the morning of 6 August 1945, Hiroshima was a historic city whose lack of military targets had helped it escape most American bombing raids. The Second World War had already ended in Europe but was still raging in Asia, with the Japanese refusing to surrender. At that instant, the American bomber Enola Gay unleashed her deadly cargo. A few minutes later, Hiroshima was wiped out in a single murderous explosion which the citizens still call pika-don - 'flash-noise'.

You might come to sightsee, but you will end up mourning. Follow Peace Boulevard across Peace Bridge to the Peace Memorial Museum, planted among the lazily expansive blossoms in the Peace Memorial Park. The museum tells the story of the bomb calmly but eloquently. The United States had casually named its new weapon 'Little Boy', and with a power of only 13 kilotons it was indeed a lightweight compared with the thousands of megatons now held in nuclear arsenals. Yet the world's first atomic attack was devastatingly effective, as the shadow of a vaporised human on the steps of the Sumitomo bank testifies. The names of 108,956 victims are inscribed on the cenotaph outside; people still die of radiation- related sickness.

Mourners have laid wreaths at the foot of the statue of a mother striving desperately to protect her children. The bleakest testimony to recent history is the scorched shell of the former Chamber of Commerce. The city has adopted this skeletal steel frame, the 'A-Bomb Dome', as its emblem. This was the only reinforced-concrete building in central Hiroshima, and endured while more fragile structures were obliterated. Even though it is ringed by young green trees, the scorched and twisted shell haunts the city skyline - a grotesquely deformed survivor of the most lethal weapon ever used.

The Obara's flat, like every other dwelling in Hiroshima, is modern and functional. In the Japanese tradition you take off your shoes at the front door and exchange them for slippers. Any ice which needed to be broken with my hosts melted away as I struggled to fit size 12 feet into standard-issue Japanese footwear. I teetered into the kitchen, where we sat and drank green tea. And talked.

Mr and Mrs Obara were born shortly after the war, and their families moved to the city when rebuilding began in the Fifties. She works in a flower shop, he is an engineer. They became one of Hiroshima's 40 host families when their children grew up and moved out. They are enthusiastic about the city's role as a centre for peace, yet modest about their own contribution to international understanding. We talked of their son who runs a sushi bar in Honolulu, they produced an old atlas for a guided cartographical tour of Britain, and I felt a stab of embarrassment about the shabby part of London where I live. Hiroshima looks clean and spacious - an awesome tribute to survival.

The evening passed swiftly and happily, and ended with a small exchange of gifts. My hosts presented me with a tin of green tea and a wooden rice spoon. As well as the usual inscription, the spoon bore the silhouette of the A-Bomb Dome. As I signed the visitors' book, Mrs Obara urged me to take a day-trip across to Miyajima - 'Little Shrine Island' - across the straits from Hiroshima.

Sacred to the Shinto religion, Miyajima is an antidote to the crushing inhumanity of warfare. From the shoreline, lapped by gentle waves, rises a torii. This ceremonial archway resembles a huge scarlet character from the Japanese alphabet, its reflection of graceful curves and symmetry dissolving into the Sea of Japan. So beautiful an image, so close to scenes of utter agony and despair, gives hope for the resilience of the human spirit.

To take part in the Home Visit System, you need to call one of the administrative offices at least a day in advance. In parallel with the Home Visit System, the 'Explore Japanese Culture' scheme aims to introduce the visitor to national crafts, such as origami, wearing a kimono or learning the martial art of kendo. Numbers for both schemes are as follows: Hiroshima 082 247 9715; Tokyo 03 3502 1461; Nagasaki 0958 233931; Nagoya 052 581 0100; Kyoto 075 752 3511; Osaka 06 305 3311. When dialling from the UK, use the prefix 010 81 and omit the 0 from the city code.

Getting there: British Airways (0345 222111) flies non-stop from London to Osaka, about 200 miles from Hiroshima. The lowest official fare in July is pounds 1,142, with a 14-day minimum stay. Tokyo is another 300 miles from Hiroshima, but fares are much lower. The fastest cheap route London- Tokyo is on Aeroflot for pounds 520 through Bridge the World (071-911 0900).

Getting around: The Japan Rail Pass allows unlimited travel on Japanese Rail trains. One week costs pounds 173. Buy it before arrival in Japan from the Japan Travel Bureau, 10 Maltravers Street, London WC2R 3EE (071-836 9387).

Where to stay: Ryokan or minshuku provide Japanese-style bed and breakfast. In Hiroshima, I stayed at the Ryokan Mikawa (082 261 2719). Single and double rooms cost pounds 22 and pounds 37 respectively.

Further information: Japan National Tourist Organization, 167 Regent Street, London W1R 7FD (071-734 9638).

(Photograph omitted)