When it comes to congestion, JR Shinjuku Station is king. This station is the Yamanote Line's undisputed champion of traffic, rowdy customers and sheer bedlam and confusion.

Shinjuku Station is the western floodgate to Tokyo. It is the duct that ushers in the crowds, controlling the ebb and flow of people into the metropolis. Some 2.7 million people use the station daily, embarking, disembarking or merely passing through.

But Shinjuku hasn't always been a major hub.

Shinjuku was originally a stopover on the way to Edo Castle, the center of feudal Japan. The town Shinjuku, known as Naito Shinjuku, was created in 1698 when the feudal lord Naito ceded part of his estate to add another stop to the Koshu Kaido (highway), one of five major arteries leading to the capital of Edo, Tokyo's predecessor.

Travelers en route to and from the bustling national center would pass through or stay in the town, which developed services to take care of a myriad of visitors' needs.

As a station, Shinjuku got its start in 1885 as one stop on Nihon Tetsudo's Shinagawa Line running from Shinagawa to Akabane. At that time, the train only ran three times a day, but the gradual influx of citizens into western Tokyo led to a need for more railways. Now, some 4,115 trains arrive at the station each day.

Today users of the station and Yamanote Line cannot be pigeonholed into any one category.

"Most of our customers only travel short distances. But with the station surrounded by a variety of places, like Kabukicho, the metropolitan government offices and department stores clustered around the south exit, this is a place where all types of people gather," station master Yoshio Itoh said.

But while Shinjuku, with its 450 employees, may not cater to a select slice of society, its typical day's traffic is somewhat predictable.

"We say that there are five rushes," said Itoh, sitting in his posh office above the east exit. "First, there are the people that are there when we open the shutters, awaiting the first train. Next is the morning commute, followed by the department store rush."

Later in the day, the suits and office ladies boomerang home, and the last surge is the late-night drinkers making a mad dash for the last train, he added.

But the stress of the crowds can spawn problems. In 1999, there was a jump in violent incidents against station employees and altercations at JR stations, and nearly 30 percent of the 162 incidents happened in Shinjuku.

This led to the station boosting the number of security personnel. So far, the number of incidents are down this year.

Shinjuku Station is many things -- a portal to Tokyo, a cultural hub, and a repository of history. It is anything but quiet.