"There was a time in Japan when courtesy was second nature. If you saw an elderly person, a pregnant woman or somebody on crutches, you would leap up and offer them your seat. These days, you pretend to be asleep and avoid eye contact at all costs.

But the spiralling decline of train-seat etiquette may be about to end with the arrival of an elite, fearless and impeccably polite “manners squadron” - to be unleashed on the Yokohama underground network in an attempt to avert a breakdown of the “Japanese way”.