Japan's Shinkansens or bullet trains are fast, very fast in fact. But there is something just as fast or even quicker than them - the people responsible for keeping the trains spick-and-span.
At Tokyo station, JR East's high-speed rail trains have to be in and out within 12 minutes. Two minutes for passengers to alight and three more for the next group to get on, leaving only seven minutes in between for cleaning.
Within those seven minutes, the red-uniformed crew from JR's train-servicing company, TESSEI, has to render the train cars spotless before passengers start boarding and the trains go on their way.
The military-like precision in which they go about their cleaning has gained worldwide attention.
How do they achieve such a high level of cleanliness within such a short period of time? I went behind the scenes to find out just how this level of efficiency is achieved.
Like the well-oiled machinery of these high-speed trains, the cleaning crews have their work routine pat down.
It all begins in the crew's office and rest area, located underneath the railway station's platforms and out of sight from regular passengers.
To get to that, I had to enter the staff entrance and then walk along a dark corridor, alongside the bottom half of the trains where you can actually see the train's wheels.
There, it is like an 'underground' network of offices, lockers and pantries.
Within the confines of their office, everything is laid out neatly: Schedules, cleaning equipment, the works.
What stood out from an otherwise seemingly normal crew rest area was that everything was labelled and numbered. I mean everything. From their carrier bags, to brooms and dustpans, right up to their cleaning cloths.
I discovered that these seemingly innocuous looking numbers are key to their efficiency.
The numbering indicates the exact train car that the equipment is meant for. For example, the label "4-4" indicates that the crew member belongs to group 4 and is responsible for car 4.
Colours also play a part in differentiating usage. Black carrier bags are for those in charge of the restrooms on board, while the blue ones are for general areas. This extends to even the cleaning cloths: Pink towels are meant for cleaning the windows, while the blue ones are for tables.
The fastidious number labelling extends to the seating arrangement when the crew is taking a break.
The crew members all have assigned seating in their break room. Where they sit will depend on the area they have been tasked to clean.
Seating arrangements are indicated with a label neatly pasted on each corner of the simple white tables. The label corresponds to the car number, and the person occupying that seat is in-charge of that section of the train car.
Besides indicating the exact train car that the person sitting there will be in charge of, the crew leader tells me that such seating arrangement allows for instant recognition of roles. And also ensures that information is passed on to the correct person. With every second making a difference if the trains are on time or not, such attention to detail is important.
This systematic, yet practical labelling contributes a great deal to the efficiency of Japan's JR East's high-speed network, allowing that quick 12-minute turnaround time for the bullet trains.
What's more, it's service with a smile as the crew go about their duties. The speed and pride in which these 'cleaning angels' do their jobs certainly reinforces the positive image of Japanese workers.
The writer's trip was made possible by the Ministry of Foreign Affairs of Japan.