Cartoonist. Born Marilyn Judith Grove in Auckland, New Zealand, she created the syndicated cartoon feature "Love Is...", originally as love notes to her future husband, in the late 1960s.
Casali left home aged nineteen to travel around Australia, Europe and the United States. In 1967 she moved to Los Angeles where she met and began a relationship with Roberto Alfredo Vincenzo Casali, an Italian computer engineer, at a ski-club where they were both taking lessons. Casali had been drawing cartoons of humorous incidents on the ski slopes, which Roberto encouraged, and she soon began adding cartoon illustrations to messages which she left for him. The very first drawing represented Casali herself with freckles, large eyes and long fair hair. She said later of these cartoons, "I began making little drawings to express how I felt... It was a little bit like keeping a diary that described how my feelings had grown." In the September 1981 Cartoonist Profiles magazine she said, "I drew a round blob of a girl who was supposed to be me, the one who was feeling all these fantastic things. Then I added a blob of a boy who was the reason I was feeling these things."
After she and Roberto became engaged, Casali took a job as a receptionist for a design company, and made up little booklets of her cartoons, which she sold for a dollar apiece. Word soon spread and the demand for "Love Is..." escalated. Eventually, the cartoons came to the attention of the Los Angeles Times, which picked them up for publication and published the first of the series on January 5, 1970, under the pen name "Kim". The cartoon's release coincided with the wave of success of the novel "Love Story" (1970) by Erich Segal, and the subsequent movie of the same name starring Ali MacGraw as a girl dying of an incurable disease and Ryan O'Neal as the student who worshiped her. The film's tag line was "Love means never having to say you're sorry"; Casali altered it into one of her most famous cartoons: "Love is... being able to say you're sorry." The cartoons proved to be very popular and were soon syndicated in the United States and overseas, being published in newspapers in fifty countries world-wide.
By 1974 the couple had two sons, Stefano and Dario, and planned to have more children. In 1975 Roberto was diagnosed with testicular cancer. Casali said: "I spent the next year fighting for a cure and trying to keep the bad news from him." She commissioned London-based English cartoonist Bill Asprey to take over the writing and drawing of the daily cartoons for her, under her signature. Asprey has produced the cartoon continuously since 1975.
Roberto died in March 1976, aged 31. The couple had been trying to have a third child, and had frozen and stored some of his sperm before his death. Despite initial opposition from the medical profession, Casali was determined to have another child by her husband. She underwent several treatments of artificial insemination at a Cambridge clinic, and gave birth to son Milo Roberto Andrea sixteen months after Roberto's death.
In the mid-1980s Casali moved her family to New South Wales, Australia, and bought a farm north of Sydney where she bred Arabian horses for several years. In 1990 she returned to England and settled in Leatherhead, Surrey.
Casali died of cancer of the bone and liver in 1997. Her son Stephano oversees the continuing "Love Is..." publications, while her sons Dario and Milo are game designers, most notably for the Doom franchise and The Plutonia Experiment.