As Kumiko Nakagawa walks through the front door of the department store, four staff members bow and say in unison " Irasshaimase". "It feels just like home," says the tourist, with a smile.

However, we are not in Japan, but close to the centre of Tainan, in the southwest of Taiwan, in what used to be the Hayashi department store. When it first opened, in 1932, its five storeys made the store the tallest building in the city and it was the only one with a lift. It was the shop of choice for the rich and powerful.

In June 2015, the building reopened after a restoration that had taken three years and cost NT$80 million (HK$19 million), with the fittings, floorboards and wooden panelling recreated in the style of the 1930s. It no longer sells global brands but handmade clothing, jewellery, tableware and other items created by local designers, as well as traditional desserts. The building's rooftop Shinto shrine has been restored and the restaurant offers "Showa spaghetti", an ordinary dish named after an extraordinary character: the wartime emperor.

Unlike North and South Korea, and Manchuria, Taiwan treasures aspects of its colonisation by Japan, which lasted 50 years (1895-1945), and has turned them to commercial use. Many buildings of the Japanese period have been preserved. A short walk from the former department store is another; the National Museum of Taiwan Literature is housed in what used to be the city government building, which is 100 years old this year.

In the east of the city, in the Xinhua district, is 80-year-old Xinhua Old Street. With its baroque architecture and relief sculptures, it is typical of streets built during the Japanese period.

"We have more historical buildings than anywhere else in Taiwan and have preserved them better," says tour guide Liang Min-chiang. Fortunately, none of them were among the 86 buildings deemed uninhabitable after the earthquake that shook the city in February.

Tainan is a city of 1.9 million people in the middle of a rich farming area. It is the oldest city on the island and was the capital for more than 200 years, until the Qing government chose Taipei instead, in 1887. It is on a north-south expressway, on the main railway line between Taipei and Kaohsiung and has a small airport.

It is a city of many attractions, but "the Japanese come to see the many buildings of their era", says Liang. "They include two shrines in the countryside. One is to a Japanese pilot whose plane was coming down; he diverted it from a village and landed in a field. The other is dedicated to a Japanese policeman who served here."

In the Yoichi Hatta Memorial Park, near Wushantou reservoir, sits a statue of the engineer who built the island's largest irrigation project, across the surrounding Chianan Plain. In May 1930, after 10 years of work, Hatta's team completed the reservoir, which can store up to 150 million tonnes of water and enabled 150,000 hectares of infertile land to be cultivated, transforming the agriculture of southwest Taiwan.

Tainan's historical buildings are not all Japanese. In the coastal Anping district is the two-storey Old Tait & Co merchant house, built by a British company. Painted white, in the Western colonial style, the building has a corridor around the front, back and sides covered with an arcade.

Anping fort, which was known as Fort Zeelandia when it was completed in 1634, by the Dutch, and consists of inner and outer fortifications, is the oldest of its kind in Taiwan. The inner fort is three storeys high, the outer, in a rectangular shape, has a cannon at each of the four corners. Next to the fort is narrow, winding Yanping Street, the first road built by the Dutch East India Company when it ruled Taiwan (1624-1662) and now full of food stalls and small shops selling souvenirs and handmade products.

The city has more Confucian - including Taiwan's first - and Buddhist temples than anywhere else on the island and there are many churches, Protestant and Catholic, because it was once an evangelisation centre.

Taiwan is a favourite destination for those for whom food is an important element of the travel experience, and Tainan holds up its end of the bargain by offering a number of well-known snacks - dumplings, shrimp rolls, stir-fried eel, pineapple cakes and coffin toast, a thick slice hollowed out to accommodate a filling - day and night, from street stalls around the city, but especially along the old section of Yanping Street.

A 25-minute drive north of the city centre is the National Museum of Taiwan History. Opened in 2011, the museum's exhibits include a banknote issued in 1895 by the Republic of Formosa, which existed briefly in the time after the Qing government gave up the island to Japan and before the army of the new coloniser arrived; and a large section on Japanese rule, showing the achievements made in industry, agriculture and education, as well as the second world war, when thousands of Taiwanese fought for Japan. Again, such an exhibition would be unimaginable in either of the Koreas or northeast China.

Director Lu Li-cheng says his museum avoids promoting any single perspective of the island's past.

"Rather it is our hope that, by illuminating many different viewpoints, visitors will be able to develop an objective view of the history of Taiwan."

Another reason to come to Tainan is the warmth and humour of its people, who know that the future of their island depends on tourism, leisure and the service sector.

"Our future is as a low-carbon country like Switzerland," says Lin Ming-wei, who works at the city's two-platform railway station. Opened on March 15, 1936, the station building is a two-storey structure. The second floor used to be a hotel, but that closed in 1965. "Most of our industry has gone offshore to [China]  and countries in Southeast Asia. So we must attract tourists from all over the world and make them feel welcome.

"Smiling and good manners are essential."