Of course, those little cartoons with a naked but asexual boy and girl sharing their mutual love – actually, in most cases the girl is crying out her admiration, loyalty and affection for the boy – may seem hopelessly romantic and utterly naive. But they are spread across the pages of newspapers the world over, collecting a fan base that remains to this day.

Even now, more than 15 years after the death of Kim Casali (1941-1997), the illustrator who invented the two characters, you can read her scribbles every morning in the largest newspapers. Her international career started on 5 January, 1970 when the comic strip Love is… was first published in the Los Angeles Times. In Flanders, Het Nieuwsblad is still publishing her work. And now, for the first time, an exhibition tells the couple’s story, as part of the International Cartoon Festival in Knokke.

New Zealand-born Casali (original name: Meredith Judith Grove) was writing these little love notes to her Italian boyfriend, Roberto Casali, whom she met at the end of the 1960s when she was living in Los Angeles; they later had three children together. “At first she just left small, loving messages for him, but encouraged by my father she started to make cartoon illustrations,” says her son Stefano, who was at the opening of the festival. “It was her way to express herself, like a diary.”

Stefano is aware of the fact there are a lot of women’s rights organisations that don’t approve of the naive way in which his mother often depicted women. “But come on, get over it,” he says. “It’s simple, it’s sweet, it’s innocent, it’s charming. That’s why so many people can identify, and why it became a worldwide phenomenon.”

Casali took advantage of her job as a receptionist for a printer company to make little booklets of her cartoons, selling them for a dollar each. The cartoons were soon syndicated and being published in newspapers in 50 countries and more than 25 languages. From 1972 you could see the couple on mugs, T-shirts and calendars, and later even in publicity campaigns, like the one asking for politeness in the London Underground.

“The characters weren’t just created for material ends,” explains Stefano. “At the exhibition you can see some of the original drawings my mother did for my father. For me it’s especially nice to see the cartoons from around the time I was born: Love is… being nice to the baby, or… not minding when the baby throws his food everywhere.”

Roberto was diagnosed with cancer in 1975 and died in 1976. At that point, Kim commissioned British cartoonist Bill Asprey to take over the daily cartoons, under her signature.

Because Casali and Asprey’s drawings are not political, it’s like entering another world when you switch exhibition rooms and see the selection of cartoons from competitions such as the Gouden Hoed, European Press Cartoon and Belgium Press Cartoon.

With more than 400 jokes about the euro crisis, political hypocrisy and human decay, and Michelle Martin bumping into former Fortis chairman Maurice Lippens in the streets of Knokke, you’re in for an immediate reality check.

Until 15 September

Beach/Casino Knokke

www.cartoonfestival.be