Expo ’70: The Six Months That Changed How Japan Saw Itself

Between March and September 1970, Japan staged the largest world’s fair in history on a former bamboo forest in the Senri Hills north of Osaka — and in those six months, a nation that had been bombed into rubble a single generation earlier formally declared itself a technological superpower, the equal of any country on earth. The declaration worked: the Japan World Exposition drew a total attendance of more than 64 million people, a record that stood as the largest among all world fairs until Shanghai surpassed it in 2010. What made Expo ’70 more than a very large trade show was the question it forced Japan to answer in public — not “what have we built?” but “who are we now, and who do we intend to become?”

Why we can tell you this — MICHI is written by an Osaka-based editorial team that can stand in the Expo ’70 Commemorative Park in Suita, walk the axis where Kenzo Tange’s space-frame roof once floated above the Festival Plaza, and look up at the Tower of the Sun from the same angle that 64 million visitors did. This piece draws on materials from the Bureau International des Expositions, the official Tower of the Sun Museum, academic work published through the BIE and the University of Pennsylvania, Wikipedia’s extensively sourced Expo ’70 entry, and contemporary reporting in English and Japanese. Where the record is contested — particularly around the political meaning of the Expo and the extent of its economic legacy — we say so plainly.

On the morning of March 15, 1970, a light snow had fallen overnight on the Senri Hills. By the time the opening ceremony began, 8,000 dignitaries were seated in a landscape that looked, to most Japanese eyes, like nothing on earth: a kilometre-long spine of steel and glass, a 70-metre concrete figure with three faces and outstretched arms punching through a vast roof, and beyond it, 116 pavilions from 77 nations arranged across 330 hectares of what had been, a few years earlier, pine forest and rice paddies.

The ceremony opened at 11:00 a.m., attended by around 8,000 distinguished and invited guests from both inside and outside Japan, and touching moments were conveyed to countries and regions all over the world by TV broadcast via satellite. Japan had arrived — and it had brought the world along to watch.

Why Did Japan Need a World’s Fair at All?

The answer begins not in 1970 but in 1945, in the specific quality of the silence that followed Japan’s surrender. Most of the major cities had been reduced to rubble by Allied bombing campaigns in World War II.

Osaka, which had become a hub of industry by the early 20th century, was one of those cities. But after the US had helped with reconstruction after the war, Japan experienced momentous economic growth from the 1950s to the 1970s, becoming one of the top economies in the world.

The speed of that recovery was genuinely without precedent. The average growth rate from 1945 to 1958 was 7.1 percent, whereas it was 9.5 percent from 1959 to 1970.

Japan’s Cabinet Office data show that the real GDP growth rate sharply increased to 11.2 percent in 1959, 12.0 percent in 1960, 11.7 percent in 1961, and so on — above 10 percent in eight of the twelve years from 1959 to 1970. As a result of this growth spurt, by 1970 Japan boasted the third largest economy.

But economic statistics do not make a national identity. The average monthly consumption of urban family households doubled from 1955 to 1970.

Refrigerators, televisions, washing machines — the “three sacred treasures” of postwar consumer culture — had moved from luxury to expectation within a single decade. Between 1950 and 1970, the percentage of Japanese living in cities rose from 38 percent to 72 percent, swelling the industrial workforce.

A country that had been overwhelmingly rural and agrarian was now, within living memory, an urban industrial nation. The question of what that nation actually stood for — what it believed, what it aspired to, how it wished to be seen — remained unresolved.

The 1964 Tokyo Olympics had been the first attempt at an answer. The Shinkansen ran for the first time on October 1, 1964, nine days before the opening ceremony.

The message was unmistakable: Japan was modern, Japan was fast, Japan was back. But the Olympics were Tokyo’s moment, and Tokyo had always been the capital, the seat of imperial and then governmental power.

The Ministry of International Trade (MITI) proposed the Expo to the Bureau International des Expositions in 1964 as a showcase for Japanese post-war recovery and modernisation, as a stimulus to further infrastructure development for the Kansai region, just as the 1964 Tokyo Olympics had stimulated redevelopment for Tokyo and the Kantō region. Osaka — the merchant city, the city of commerce, the city that had always been slightly suspicious of Tokyo’s pretensions — was going to have its own moment, and it was going to be bigger.

Why Osaka, and Why These Particular Hills?

The choice of the Senri Hills, about 13 kilometres north of Osaka’s city centre, was not accidental. Expo 1970 Osaka was one part of a massive infrastructure development of the Suita region during the apex of the high growth era in Japan (1955–1972), which included the extension of the Hankyū Senri railway line (completed 1967), construction of the Meishin Expressway (1963–65), and the development of the Senri New Town, a planned development of over 1,000 hectares adjacent to the future Expo site, built to accommodate a population of 150,000, whose first units opened in 1962.

In other words, the Expo did not arrive in a vacuum. It was the capstone of a decade-long project to urbanise the northern fringe of Osaka, to push the city’s footprint into territory that had previously been agricultural.

The fair gave that project a deadline, a budget, and a global audience. In the run-up to the Expo, 110 kilometres of new roads were completed in the region, and key infrastructure was upgraded throughout the city.

The research published through the journal Planning Perspectives puts the total infrastructure investment figure at eight billion dollars — a number that dwarfs the cost of the fair itself.

There was also a symbolic dimension to the site selection. Japan had originally wanted to host a World Exposition in 1940, but it was cancelled with the escalation of the war.

The one million people who had bought tickets for 1940 were allowed to use them in 1970. The 1940 exposition had been planned to celebrate the 2,600th anniversary of the founding of the Japanese imperial line — a piece of nationalist mythology that the war had made impossible to stage.

By 1970, the event marked the traditionally accepted 2,600th anniversary of the founding of Japan (delayed from the actual event in 1940 by World War II), the centennial of Japan’s entry into the worldwide economic sphere, and the unprecedented rise of Japan as an economic power in the post-war world. The Expo was, among other things, a delayed celebration of national continuity — a way of saying that the interruption of the war years had not broken the thread of Japanese civilisation.

Why Did the Architecture Look Like That?

Stand in the Expo ’70 Commemorative Park today and look at the Tower of the Sun, and you are looking at a building that should not exist — not because it is ugly (though opinions differ sharply on that point), but because it was designed to be temporary. Almost everything else from 1970 was demolished. The Tower survived because it was too strange, too powerful, too deeply embedded in the national imagination to tear down.

To understand why the Expo looked the way it did, you need to understand Metabolism — the Japanese architectural movement that treated cities as living organisms rather than static objects. Master-planned by architectural legend Kenzō Tange, the entire landscape of the Expo 1970 embodied the principles of the design philosophy known as “Metabolism,” Japan’s most significant contribution to 20th-century architectural theory. The Metabolists, including Tange, Kishō Kurokawa, and Kiyonori Kikutake, mimicked the biological metabolic process in their designs and envisioned cities as living organisms capable of growth and adaptation rather than static structures.

The movement had been born in the late 1950s among a group of young architects who were students of Tange. Metabolism is an architectural movement founded in Japan between the late 1950s and early 1960s.

Four young architects formed the group — Kiyonori Kikutake, Kisho Kurokawa, Fumihiko Maki, and critic Noboru Kawazoe — all heavily influenced by their professor, the national superstar-architect, Kenzo Tange. The main idea was to rethink society using architecture as a tool for potential change.

The Expo was the movement’s one chance to build a real city, even if only for six months. Although almost none of the Metabolists’ ambitious schemes of city design was carried out — with the only exception of the Osaka Expo, a six-month trial of the future city — their urban utopias constitute invaluable intellectual legacy from the 1960s.

Tange’s master plan gave the site a central “spine” — the Symbol Zone — from which circulation paths branched outward like arteries from a heart. Sprawled across 330 hectares in the Senri Hills, the Expo site was master-planned by Kenzo Tange and Uzo Nishiyama, two key figures of Japan’s 1960s Metabolist movement.

In line with this experimental spirit, the site was conceived with a central spine designed to inspire the centre of a future city. Named the Symbol Zone and spanning one kilometre long by 150 metres wide, this central axis featured the Festival Plaza, the Tower of the Sun, the Theme Pavilion, and the Expo Tower.

The BIE’s detailed architectural history of Expo 1970 describes how Tange’s former student Arata Isozaki was placed in charge of the Festival Plaza’s event systems, designing not permanent architecture but an interactive “environment” — featuring moveable lighting suspended from trolleys mounted in Tange’s space frame roof, moveable stage and seating components, and two giant robots, nicknamed Deme and Deku, to assist with the staging. This was not decoration. It was a prototype for a new kind of urban space, one that could reconfigure itself in response to human use.

The Tower That Refused to Cooperate

Into this sleek, technocratic vision, Taro Okamoto inserted something that refused to fit. The Tower of the Sun was not a Metabolist building. It was not a building at all in any conventional sense — it was a 70-metre sculpture with a face on its belly, a golden mask at its crown, and a black sun on its back, its arms spread wide as if it were about to embrace or devour everything around it.

The Tower of the Sun was designed by the artist Taro Okamoto, and was constructed as part of the Theme Pavilion in the Symbol Zone of the 1970 Japan World Exposition in Osaka — along with the Tower of the Mother, the Tower of Youth, and the Big Roof. The Big Roof, designed by the architect Kenzo Tange, had a length of 292 metres (north-south), a width of 108 metres (east-west), and a height of approximately 40 metres. The Tower of the Sun punched straight through this roof, violating the geometry of the master plan with something that looked like it had arrived from a different civilisation entirely.

That was precisely the point. Three spaces — the underground for the past, the ground for the present, and the mid-air for the future — would organically resonate with one another while existing independently and express one magnificent vision of the universe together.

This idea was related to the mandala, the Oriental concept of the universe. Okamoto was not interested in progress as the engineers defined it.

He was interested in the deep time of human existence — the primitive, the irrational, the ancient energies that technology could not replace.

The Tower of the Sun bears three faces: the “Golden Mask” located at its top, which shines golden and suggests the future; the “Face of the Sun” on its front, which represents the present; and the “Black Sun” on its back, which symbolizes the past. Inside, a 41-metre steel sculpture called the Tree of Life — adorned with nearly 200 creatures ranging from single-celled organisms to giant mammals — traced the entire arc of biological evolution.

You entered the Tower from below, through an underground exhibition representing the origins of life, and emerged into the future through Tange’s space frame roof above. The journey was vertical, temporal, and deliberately overwhelming.

In 2020, the Tower of the Sun was designated a national registered tangible cultural property by Japan’s Agency for Cultural Affairs, recognizing its architectural and artistic significance as the symbol of Expo ’70. The designation came fifty years after the fact, but it confirmed what Osaka had known for decades: the Tower is not a relic of 1970. It is a permanent statement about what it means to be human.

Why Did 64 Million People Come?

The raw numbers are staggering even by contemporary standards. The Expo ’70 drew a record-breaking total of 64,218,770 visitors across its 183 days from March 15 to September 13, 1970, establishing it as the most attended world’s fair at the time.

This equated to an average daily attendance of 350,000, with peaks reaching 836,000 on September 5, 1970. Visitor demographics reflected strong domestic interest, with approximately 62.5 million Japanese attendees and 1.7 million foreigners, comprising about 2.7% of the total.

That domestic dominance is the key figure. Around sixty per cent of the population of Japan would eventually visit the Expo.

This was not a tourist attraction in any conventional sense — it was a national pilgrimage. For most Japanese visitors in 1970, the Expo was the first time they had encountered the physical presence of foreign cultures at scale.

With 77 participating countries, Expo 1970 Osaka was a unique opportunity for the Japanese public to “travel the world” and discover the culture, art and achievements of foreign nations. Among the most popular pavilions were those of many newly independent African and Asian countries, many of which were participating in a World Expo for the first time.

The star attraction, by almost any measure, was a rock. The star attraction of the U.S.

pavilion, possibly even the entire fair, was a rather unremarkable-looking two-pound rock. Its provenance gave this particular rock star appeal: on November 20, 1969, Apollo 12 astronaut Alan L.

Bean found the rock on the rim of Head Crater in the Moon’s Ocean of Storms. Lines to view the Moon rock could be as long as two hours; by some accounts, many fairgoers attended just to see it.

On opening day, 8,000 visitors per hour poured into the pavilion. The Moon rock welcomed an average of 80,000 visitors per day, and a total of 14 million people saw it.

The moon rock’s appeal was not merely novelty. It arrived at the Expo less than a year after the first moon landing, at the precise moment when the Cold War competition between the United States and the Soviet Union was being played out in space.

Both superpowers had enormous pavilions at the Expo. Both the American and the Soviet pavilions highlighted the exploration and future development of space.

The Osaka Expo of 1970 would be the last world exposition attended by the Soviet Union. For Japanese visitors, standing between these two giants and watching them compete for attention, the experience was both thrilling and clarifying: Japan was not a superpower in that sense, but it was the host, the convener, the nation that had made all of this possible.

Why Was the Technology So Radical?

The technologies on display at Expo ’70 read today like a checklist of the modern world. Several new technologies, such as the first IMAX large-format movie, early mobile phones, local area networking, and magnetic levitation (maglev), debuted at the Osaka Expo.

Consider what that list actually means. NTT’s Electronics and Telecommunications pavilion introduced visitors to “The Dream Telephone” — bulky white handsets that allowed users to make calls from anywhere on the Expo grounds while seated in transparent plastic “eggs.” This represented one of the world’s first public demonstrations of mobile telephone technology. Though the technology bears little resemblance to our sleek smartphones, it helped kickstart the mobile communication revolution we now carry in our pockets.

The corporate pavilions were equally ambitious. The eye-catching Fuji pavilion — an air-inflated membrane structure — featured the world’s first IMAX, while the Metabolist Takara Beautilion pavilion encapsulated the concept of impermanent, modular architecture.

The Beautilion’s construction method was itself a demonstration: one prime example of the metabolism application was the Takara Beautillion by Kisho Kurokawa. The construction of the pavilion involved fitting rectangular units pre-manufactured in a workshop into the main frame, and the work onsite took just seven days.

The downstream consequences of that modular thinking were immediate. An Osaka business owner was especially impressed by the metabolism-inspired pavilions at the Expo, and later consulted with Kurokawa, who ended up launching the world’s first capsule hotel. The capsule hotel — now a fixture of Japanese urban life and a global design export — was born directly from the architectural experiments of Expo ’70.

And then there was the food. Conveyor belt sushi started in Osaka Prefecture in 1958, and became a lot more popular after it was served at Expo ’70.

Conveyor belt sushi made its world debut at the 1970 Osaka Expo — and the format that now feeds millions of people daily in restaurants from Tokyo to London was, in 1970, a curiosity that fairgoers queued to try. The Expo was not just a showcase for technology.

It was a laboratory for the future of everyday life.

The entire site was also, remarkably, networked. The entire Expo operated on a networked computer system that tracked visitor flow, located missing children, and managed traffic patterns — essentially functioning as the operating system for a city-scale device — a precursor of today’s smart urban infrastructure by decades.

In 1970, this was not a selling point that most visitors would have understood. It was simply infrastructure.

But it was infrastructure of a kind that the rest of the world would not build for another generation.

Why Was the Expo Also Contested?

The official narrative of Expo ’70 — national triumph, technological optimism, peaceful internationalism — was never the only story being told. The fair opened in the same year that the US-Japan Security Treaty (Anpo) came up for automatic renewal, and the political temperature in Japan was high.

Projections of nationalism by the Japanese government were especially suspect to the citizenry due to the controversy surrounding the US-Japan Security Treaty — also known as Anpo — which allowed American military bases to operate on Japanese soil. When Anpo was revised in 1960, it ignited the fiercest protests post-defeat Japan had ever seen, with hundreds of thousands surrounding the National Diet and an estimated 30 million participating in protest actions across the nation. With the treaty up for renewal in 1970, the movement was revived, if at smaller scale, and Expo ’70 became symbolic for many of all that was wrong with so-called “progress” in the archipelago.

The 1970 World Exposition in Osaka has been seen as an ideological performance that assuaged and coopted political, social, and artistic protest movements in the 1960s through the mobilization of citizens behind economic development policies and the promotion of depoliticized consumer lifestyles. This reading — advanced by scholars including those whose work appears in the academic journal Review of Japanese Culture and Society — sees the Expo as a kind of managed spectacle, a way of channelling the energies of a restless, politically divided society into the safe harbour of consumerism and national pride.

The critique had real force. Student activists, environmental groups, and leftist organizations protested against the Expo, criticizing its high costs, potential environmental damage to the Senri Hills site, and perception as a symbol of technocratic excess and government priorities amid ongoing social and political unrest in Japan during the late 1960s.

Demonstrations were staged in Shinjuku and Kyoto by a group known as the Expo ’70 Destruction Joint-Struggle Group. Unlike Japanese student demonstrations of 1968, the protests — whilst theatrical — were nonetheless relatively peaceful and were limited to participants collectively holding hands and running towards buildings or standing in the streets shouting slogans at passersby.

But the critique also had limits. Taro Okamoto himself was not a government propagandist — he was a genuine avant-garde artist who had spent years in Paris absorbing Surrealism and who had returned to Japan with a deep suspicion of the kind of smooth, technological optimism that the Expo’s corporate pavilions were selling.

His Tower was, in a sense, the protest inside the fair: a reminder that the past could not be abolished by progress, that the primitive and the irrational were not problems to be solved but energies to be honoured. The fact that the government commissioned him anyway, and that his Tower became the Expo’s defining image, suggests that the relationship between official culture and artistic dissent in 1970 Japan was more complicated than either side liked to admit.

Why Did the Expo Change How Osaka Saw Itself?

The physical transformation of the Senri region was the most visible legacy. The impact of Expo ’70 on Osaka was explosive.

New expressways, train lines and neighbourhoods sprang up. The entire Senri region urbanised rapidly.

The city’s image changed: from smoky merchant hub to a beacon of modernity.

But the deeper transformation was psychological. For most of the postwar period, Osaka had existed in Tokyo’s shadow — the second city, the commercial city, the city that made things and sold them but did not set the cultural agenda.

The Expo changed that calculus. The Expo contributed significantly to the urban development of Osaka and the Kansai region, propelling it to a status capable of rivalling the economic and cultural hub of Tokyo.

The cultural residue was equally significant. The influx of foreign ideas, foods, fashions and languages planted seeds.

People tried spices. They got passports.

They looked outward. Expo ’70 helped open up Kansai minds.

For a generation of Japanese who had grown up in a country that was, by necessity and by policy, largely closed to the outside world, the Expo was the first encounter with the sheer variety of human civilisation. It was not a substitute for travel — it was the thing that made people want to travel.

The Expo also produced one of the most extraordinary acts of temporal ambition in modern history. In January 1968, two Japanese companies — Panasonic Corporation and The Mainichi Newspapers — agreed to undertake a joint time capsule project in celebration of the Japan World Exposition 1970.

After three years of planning, research and construction, two time capsules identical in every detail were buried adjacent to Osaka Castle. The lower capsule will remain buried for 5,000 years; the upper capsule will be opened for the first time in the year 2000 and every 100 years thereafter.

The purpose of the project is to send forward in time a visual, aural and documentary record of life in the year 1970 AD. Each capsule contains 2,098 objects and recorded items representing the achievements of civilization and the everyday experience of the Japanese people.

The Panasonic Time Capsule project page preserves the full record of what was chosen to represent Japan to the future. The act of choosing was itself a form of self-definition: this is who we are, this is what we value, this is what we want remembered.

Why Does the Expo Still Live in Japanese Culture?

Expo ’70 has a peculiar afterlife in Japanese popular culture that goes well beyond nostalgia. Expo ’70 appears in Shōwa nostalgia fiction, where it is used as a symbol of the financial prosperity of Shōwa era Japan. For example, Expo ’70 plays a central role in the plot of Naoki Urasawa’s manga 20th Century Boys; and various Expo ’70 pastiches are featured in Crayon Shin-chan: The Storm Called: The Adult Empire Strikes Back.

The Tower of the Sun, specifically, has become a kind of cultural shorthand for a particular quality of Japanese ambition — the willingness to build something enormous, strange, and unapologetically itself. It appears in manga, in films, in architecture criticism, in the work of designers who were children in 1970 and who have spent their careers trying to understand what it meant. The former Expo 1970 venue is a historical site that symbolises Japan’s post-war recovery, and the exhibition halls that remain standing and other legacies of the Expo are valuable parts of cultural heritage — a view now formalised by the Japanese government’s cultural property designation.

The Expo also established a template for how Japan presents itself to the world. The 1964 Olympics had been about speed and efficiency.

Expo ’70 was about something more complex: the coexistence of the ancient and the futuristic, the primitive and the technological, the national and the universal. That tension — between Japan’s deep cultural particularity and its ambition to participate fully in a globalised modernity — is still the central tension of Japanese public culture.

Expo ’70 did not resolve it. It staged it, magnificently, for six months in the Senri Hills, and then left the Tower standing as a permanent reminder that the question had not been answered.

Why Should a Discerning Traveller Care?

The easy answer is that the Expo ’70 Commemorative Park is a genuinely unusual place to spend a day — 264 hectares of forest and garden, the Tower of the Sun at its centre, the Expo ’70 Pavilion (housed in the original Steel Pavilion) offering one of the best museum experiences in the Osaka region, and the National Museum of Ethnology, one of the world’s great collections of material culture, sitting quietly at the park’s edge.

But the deeper answer is that Expo ’70 is one of the few places in Japan where you can stand inside a specific historical argument. The park is not a reconstruction or a theme park version of 1970.

It is the actual site, with the actual Tower, in the actual landscape that was carved out of bamboo forest to make a point about what Japan was and what it intended to become. The argument it was making — that a nation destroyed in 1945 could, within a single generation, host the largest world’s fair in history and introduce the world to mobile phones, IMAX cinema, and capsule architecture — was not a modest argument.

It was an extraordinary one, and it turned out to be correct.

Standing in front of the Tower of the Sun, you are also standing in front of a question that Taro Okamoto was asking the technocrats around him: what is progress actually for? The Tower’s three faces — past, present, future — refuse the linear narrative of improvement that the corporate pavilions were selling.

They insist that the past is not behind us but beneath us, that the future is not a destination but a mask we wear over our ancient faces. In 2026, with Osaka having just hosted its second World Expo on a man-made island in the bay, that question feels more urgent, not less.

The traveller who makes the 40-minute journey from Umeda to Banpaku-kinen-koen Station on the Osaka Monorail — the same monorail line that served the original Expo — and walks through the Central Gate into the park is not visiting a museum. They are entering a conversation that Japan has been having with itself for more than fifty years, about what it means to be modern, what it means to be Japanese, and whether those two things can be reconciled without losing something essential. The Tower of the Sun, arms spread wide, three faces watching in three directions at once, has been waiting patiently for an answer.

Frequently Asked Questions

Q: Can I visit the inside of the Tower of the Sun?
A: Yes — the interior has been open to the public since March 2018, after extensive restoration. Admission to the Tower of the Sun Museum is by reservation only, and reservations must be made at least one day in advance of your desired tour date.

Book via the official Tower of the Sun Museum website. Weekend slots fill quickly; book as far ahead as possible.

Q: What is the Expo ’70 Pavilion?
A: The Steel Pavilion — which still stands in the park that was transformed after the Expo — was repurposed as an Expo 1970 Pavilion to exhibit materials related to the Expo. It holds models, posters, maps, and artefacts from the original fair and is one of the most informative small museums in the Osaka region.

Q: How does Expo ’70 relate to Expo 2025?
A: While Expo 1970 showcased technology’s power to transform human life, Expo 2025 shifts focus to how innovation can heal and protect our planet — reflecting how priorities have evolved across generations. The 1970 fair was held in the Senri Hills; Expo 2025 was staged on Yumeshima, a man-made island in Osaka Bay. The two events are bookends to a half-century of Japanese self-examination.

Q: Is the park worth visiting even without a Tower of the Sun reservation?
A: Absolutely. The park is a sprawling space where visitors can enjoy history, culture, nature, and recreation all in one place.

In addition to cultural facilities that preserve the legacy of Expo ’70, the park offers beautiful natural scenery, adventure playgrounds, and even hot springs. The National Museum of Ethnology alone justifies the journey.

Q: What technologies from Expo ’70 actually became part of everyday life?
A: Some of the technologies exhibited at the Expo soon became popularised and are now widely used across the world. Among these are the mobile phone — showcased and tried out by visitors in the NTT pavilion — as well as the popular “Washlet” Japanese toilets with integrated heating and bidet functions. The experimental pavilion designs inspired architects and planners around the world, with the modular Takara Beautillion being the direct inspiration for the world’s first capsule hotel only a few years later.