Brazilian-born, Mr Gyger is a prize-winning Swiss historian and writer who, since 1999, has been director of the "House of Elsewhere", a Swiss museum housing one of the world's largest collections of literature relating to science fiction, utopia and extraordinary journeys.
Ms Harger grew up in Dunedin, living initially at Port Chalmers and attending Queen's High School before studying at the University of Otago.
She has lived in Europe since 1999 and these days lives in Brighton, England, where this year she became director of the Lighthouse, a leading film and media agency which fosters and helps exhibit "excellent digital art and film".
The couple, who met at a European Space Agency space technology conference in the Netherlands in 2004, are in Dunedin this week for a special reason.
On Saturday, New Year's Day, they will be married at the Port Chalmers Town Hall.
And they are also jointly curating an exhibition involving about 30 works by artist friends from Dunedin and abroad which will be displayed in the hall for the wedding.
Some of their favourite musicians will perform during the festivities.
A kind of mini-United Nations, a gathering of about 100 friends from 10 countries, including Switzerland, the United Kingdom, and the United States, will converge on Port Chalmers to attend the wedding.
"It's one way to bring our two worlds together," Ms Harger said.
"We want to show them some of the extraordinary artistic heritage of Dunedin."
Since the couple met, they have lived in different countries - mainly Switzerland and England - and have become expert in commuting from country to country so they can spend quality time together.
And even after they are married, they will still live much of the time apart geographically - he in a new post as director of a National Centre for the Arts in Nantes, France, and she in England.
They are both clear about the importance of their relationship and use all the means at their disposal to maintain it, including electronic gadgets and long-distance buses, trains and planes.
"We're quite used to being part of the so-called Easy Jet [budget airline] set," she said.
Two recent incidents - the aircraft disruption caused by volcanic ash clouds from Iceland in April and unusually heavy snowfalls in Britain and Europe in recent weeks - have reminded them of the occasional fragility of travel networks.
But they point out that the excellent transport networks in Europe, the availability of fast and reliable means of travel and the relatively modest distances involved mean they can readily get together at the weekends.
"It's not that much trouble as long as there's some form of reliable transport between the cities, " Mr Gyger said.
But their time apart added to the enjoyment of spending time with each other, and there was no staleness in the relationship.
"And it's making the most of the time that we have together," Ms Harger said.
