For Eiji and Kumiko Ishikawa, the working day starts as early as 5 a.m. Having loaded the requisite equipment into their van, they set off for their first job of the day, a 14-story high-rise in western Tokyo.

They unload mops and brushes, roll out the hoses, and plug in the industrial polisher and fan as they go about their work cleaning each floor of the building, forgoing the use of elevators in favor of the stairs as a courtesy to residents.

There's a youthfulness about their efficiency and vigor, which is only remarkable in that the Ishikawas are both in their 70s.