(Picture taken from mylifeasagrape.blogspot, original source unknown)
It was first published in 1970 under the pen name Kim.
It is said that at the height of it's popularity, it may have been earning Casali, £4 to£5 million a year!
Roberto Casali was diagnosed with terminal cancer in 1975. Kim then asked British cartoonist Bill Asprey to continue her cartoon. Kim Casali died in 1997, her son Stefano then took over intellectual rights of 'Love is...'
(Above information taken from Wikipedia, not further checked for accuracy.)
(Taken from YouTube. Not my work)