Shinjuku Station swallows around 3.6 million people every single day. It’s the busiest train station on the planet. West of it sits the Tokyo Metropolitan Government Building. East of it, Yasukuni Avenue glows with multi-story buildings stuffed with bars, clubs, restaurants, and everything else that makes Shinjuku feel like Tokyo’s beating, slightly unhinged heart.
And right behind those bright lights is Kabukicho — Japan’s largest entertainment and red-light district. Thousands of bars, host clubs, girls’ bars, karaoke joints, and places that carefully tiptoe around the law. At one point in the early 2000s the area supposedly packed in around 8,000 different businesses and a couple hundred yakuza offices.
It feels like it’s always been this way. It hasn’t.
Barely 160 years ago, this was barely anything at all.
It Literally Means “New Post Town”
The name gives it away. 新宿 — Shinjuku — means “new post town.”
In the early 1600s, Tokugawa Ieyasu turned the swampy castle town of Edo into the center of Japan. He set up five major highways leading into the capital, each lined with official post towns (shukuba) where travelers, messengers, and samurai retinues could rest, change horses, and… unwind.
The area that became Shinjuku sat just outside Edo’s western gate on the Koshu Kaido road. For the first century of Tokugawa rule it was mostly farmland and a secondary mansion belonging to the Naito clan. The nearest proper post town was a long, inconvenient 10 kilometers farther west.
In 1697, a group of merchants from Asakusa saw an opportunity. They petitioned the shogunate to open a new post town closer to the city. Permission granted. By 1699, Naito Shinjuku was open for business near the fork where the Koshu Kaido met the Ome Kaido. One of the surrounding villages that had to supply labor and horses was called Tsunohazu. Today we call it Kabukicho.
The post town stretched about a kilometer from what is now Shinjuku 3-chome toward Yotsuya, ending at the big wooden-and-stone Yotsuya Okido gate that controlled entry into Edo itself.
Already a Party Town in the 1700s
Officially, post towns existed to move people and packages. Unofficially, a lot of their money came from entertainment. Inns and teahouses employed meshimori-onna — “meal-serving women” who served food… and other services. Naito Shinjuku quickly became known for its drinking and pleasure spots. Day-trippers from inside Edo started coming out just for the nightlife.
The shogunate was not thrilled. Prostitution was supposed to be confined to the official Yoshiwara quarter. Moral panics came and went. In 1718, after only 19 years, the government shut Naito Shinjuku down as an official post town. Fires, debt, and a reputation for loose living all played a part. There’s even a dramatic (and possibly exaggerated) story about a Naito family member getting beaten up after causing trouble at one of the inns, leading the clan head to demand the place be closed.
It stayed closed for more than 50 years.
In 1772 the shogunate changed its mind. The surrounding farmland was developing, traffic on the road was increasing, and the official post towns were struggling financially under strict price controls. The ban on post-town prostitution was relaxed. Naito Shinjuku roared back to life and became a proper feudal entertainment hub — basically the same spirit that still defines the area today.
Earthquake, Trains, and a Total Makeover
The post-town system collapsed with the Meiji Restoration. When Perry’s black ships forced Japan open and the Tokugawa regime fell, Edo lost half its population almost overnight. The old post towns withered.
But Shinjuku didn’t die.
In 1885 a modest little station opened on the western side of the old post town. At first it was tiny — two-car steam trains every hour and a half, sometimes with zero passengers. Foxes still lived in the surrounding fields. The big change came after the Great Kanto Earthquake of 1923. The old eastern downtown was devastated. People and businesses flooded westward. Department stores like Mitsukoshi and Isetan moved in. By 1927 Shinjuku Station was already the busiest in Japan.
The old pleasure businesses shifted into the back streets but never disappeared. Shinjuku kept its reputation as the city’s biggest red-light area even after prostitution was fully banned after the war.
It also picked up a less glamorous nickname for a while: “the anus of Tokyo.” Night-soil collectors still hauled human waste out of the city by cart, and Shinjuku sat right on the edge between urban and rural. The streets were regularly clogged with the stuff (plus horse dung) heading out to the farms.
The Interwar Party Years
By the late 1920s and 1930s, Shinjuku was becoming a real cultural destination. Cinemas, theaters (including the famous Moulin Rouge Shinjuku-za), the original Kinokuniya bookstore, and places like Nakamuraya that introduced authentic Indian curry to Japan all helped give the area a modern, slightly bohemian edge. It was overtaking older entertainment districts like Asakusa in popularity.
Then the war years crushed the party. Rationing, drafts, bans on dance halls and foreign words, military police watching performances… the nightlife went dark. The district itself would later face the bombs.
But the bones of the place — the old post-town location, the train hub that exploded after the earthquake, the long tradition of paid companionship and late-night drinking — survived.
What we see today when we step out of Shinjuku Station into the neon and the chaos isn’t some random modern invention. It’s the latest version of a “new post town” that has been selling rest, drinks, conversation, and whatever else travelers wanted for more than 300 years.
The scale is different. The technology is different. The energy feels the same.