Origin of the Kit Kat®
The origin of name of the Rowntree's now Nestle's Kit Kat® is believed to be in an early 18th century English gentlemen's club called the "Kit Cat Club", after its proprietor Mr. Christopher Catt who provided sustenance -- Kit Cats -- which where given an abbreviation of his name.
Here above the members can be shown performing the traditional toasting or roasting of a young girl, Lady Mary Pierrepont, who is being made to stand on a chair, with their Kit Kats, which were made available only to the male clientèle.
Lady Mary Pierrepont, later Lady Mary Wortley Montagu, understandably, grew up to be a women's rights activist who introduced small pox vaccinations into the UK. She travelled to the orient which she wrote about with praise. She penned "Letters from Turkey" and "Woman not Inferior to Man."
The Kit Kat Club was located at one time in Hampstead where the Kit Kat House stands to this day (photo). Since I think Japanese travel to famous named places, often associated with origins, I think that Kit Kat House is a potential Japanese tourist destination, especially if there were speciality flavour Kit Kats (of which the Japanese have many, including sweet potato flavour) were on sale.
Kit Kat's are popular in Japan since they do not have as many calories as pure chocolate bars and because their name puns on the Japanese words for definitely win, (kitto katsu) and so are given to high school students taking Japanese university entrance examination as sustenance and a good luck charm. But, little do they know the origin of the Kit Kat.
Altered image originally by Charles Green is believed to be in the public domain.