Patronage is not a new idea. Men with money have been supporting women without it, in exchange for company of varying warmth, since roughly the invention of money. Japan just kept better records.

A geisha had a danna – a wealthy patron who paid for her training, her kimonos, her debut, and in return received her attention in whatever form the two of them settled on. Meiji Japan went one better: the mekake, or official mistress, was written into the 1870 legal code as a relative of the second degree, the same rank as a wife. Twelve years later someone read the code again and quietly took it out, but for a while Japan had the only legal system in the world in which "and this is my mistress" was a statement of family law.

The modern version starts in the mid-1990s with enjo-kōsai – "compensated dating" – which ran on telephone clubs, pagers, and schoolgirls, and produced the kind of moral panic that Japanese television does better than anyone. Then the internet arrived, the deai-kei dating sites moved it all online, and it became the Wild West. It was, far too often, the underage Wild West. In 2003 the government stepped in with a law on dating sites that made platforms check ID, and – this is the clever part – gave everyone involved a layer of plausible deniability. Money changes hands for a date. What happens after the date is nobody's business, least of all the app's.

Then in 2017 Fuji TV made a drama and called it, with admirable directness, Papa-katsu. The name stuck. The 2020s added smartphones, and here we are: a thriving, semi-respectable, thoroughly Japanese institution in which women in their twenties post profiles saying they'd like to meet a gentleman for dinner, and men in their fifties reply saying they are that gentleman, and everybody understands that dinner has a clause (b).

I read all this at 62, widowed, two grown children, a good career in IT but a fairly empty calendar, and I thought: university-age women will go on dates (and possibly more) with middle-aged men, provided the men are solvent and not obviously insane?

I'm solvent at least, and working on the other one. So I guess there's only one way to find out.