The vast rail network that criss-crosses subterranean Tokyo can be a confusing and intimidating place for the uninitiated.
Dreary, utilitarian stations drone and chime with a stream of announcements, seemingly ignored by the mass of humanity that spills onto platforms or crams improbably into carriages.
It may not be pretty, but in a city where millions of commuters travel by train daily, it boasts the precision of a finely-crafted Swiss watch, keeping Tokyo moving - even if it means pushing hundreds of people into a single carriage at rush hour.
Huge banks of computing power link 13 lines and nearly 300 stations over 195 kilometres of track, putting one train on each line every two-to-three minutes at peak times.
Subway officials say that Tokyo's business culture and the value its people place on punctuality pushes them to achieve the kind of precision that foreign underground railways cannot easily replicate.
"The subway is an integral part of everyday life in Tokyo. This level of safety and punctuality is expected by our passengers," said Shogo Kuwamura, a spokesman for Tokyo Metro.
The city actually has two public subway operators: Tokyo Metro and Toei Subway. Between them they carry nearly 10 million passengers daily.
Both systems operate in coordination with above-ground trains, which themselves link several hundred stations and ferry 26 million people around all corners of the sprawling megalopolis of Greater Tokyo, home to around 35 million people and the largest conurbation on Earth.
These layers of interconnecting rail systems make punctuality all the more important - a minor delay on one train can have a knock-on effect on another service, which in turn throws several more out of kilter, each one of them setting off its own ripple effect.
But when delays do occur - even as little as a minute - they are repeatedly announced to passengers along with humble apologies until normal service resumes.
Prolonged delays are fodder for local, if not national, news programmes, and see the train companies handing out cards to passengers that they can submit to their bosses as a reason they were late for work.
"If there is a delay, you have to catch up," said driver Shunsaku Hagita, 27. "You apply your skills so that you can recover from delays."
Subway trains are increasingly operated by computers and monitored by the central command centre to minimise the risk of human error, Hagita said.
Drivers sit in the cockpit essentially to provide human eyes to monitor the on-deck computers and to take action in emergency situations, he said. In the event of an earthquake warning, all trains automatically stop.
If a subway line is delayed, other trains in the affected area drop their speed slightly, to keep them in line and maintain the flow of passengers from station to station.
The method prevents waiting passengers overcrowding platforms and jamming into delayed trains when they arrive.
A dream job
Drivers and platform attendants perform elaborate rituals at each station to demonstrate they are paying attention to subway safety.
In their cockpit, white-gloved drivers chant to themselves as they acknowledge and drive by safety signs in tunnels and to confirm readings on various onboard gauges.
Before signalling "safe to start" to drivers, conductors must raise their arms and point a finger to the closed doors, loudly demonstrating to onlookers they have checked the doors are safely shut.
For Japanese boys, the train driver sits alongside footballer, doctor and policeman as a dream job.
"I grew up watching train drivers do all that," said Hagita. "There was nothing unnatural about this when I began working as a driver.
"When I get married and start a family, I want them to ride on my train," he said.
The system played a proud part in Tokyo's successful tilt at hosting the 2020 Olympic Games, with bid chiefs pointing out that the city's "rail structure is one of the best in the world and continues to expand and develop."
The culture of extreme punctuality might be difficult to export, but Tokyo Metro has shared its know-how with foreign counterparts who are trying to improve their systems at home.
A Chinese delegation came recently to learn how to minimise train noise through better maintenance work. An Egyptian firm asked about efficient methods to stock repair parts.
Tokyo Metro, which uses one of most energy-efficient subway trains in the world, is also helping Vietnam to launch a new subway system in Hanoi.
But for all their efficiency and punctuality, there is no getting away from the fact that Tokyo's subways are a bit of a squeeze.
For Tokyo Metro, trains typically consist of up to 10 carriages that are designed to carry about 150 passengers each. During rush hour, train operators literally push nearly 300 people into a single carriage, with briefcases and handbags squeezed in as doors slide shut.
While violent crimes are extremely rare - most drunkards are asleep - young women on packed trains complain about being groped.
Subways and many other commuter trains have designated women-only carriages during the busiest hours in the morning to give them an environment free of potential perverts.
Signs requesting mobile phones be silenced are adhered to, and train rides can be tranquil experiences in Tokyo - if you can find a seat.
"We are always considering ways to improve our system," said Kuwamura.