Japan's under-40s appear to be losing interest in conventional relationships. Millions aren't even dating, and increasing numbers can't be bothered with sex. For their government, "celibacy syndrome" is part of a looming national catastrophe. Japan already has one of the world's lowest birth rates. Its population of 126 million, which has been shrinking for the past decade, is projected to plunge a further one-third by 2060. Aoyama believes the country is experiencing "a flight from human intimacy" – and it's partly the government's fault.

The sign outside her building says "Clinic". She greets me in yoga pants and fluffy animal slippers, cradling a Pekingese dog whom she introduces as Marilyn Monroe. In her business pamphlet, she offers up the gloriously random confidence that she visited North Korea in the 1990s and squeezed the testicles of a top army general. It doesn't say whether she was invited there specifically for that purpose, but the message to her clients is clear: she doesn't judge.