Niijima Gakuen Junior College Research Building (former

A Cylindrical Time Capsule of 1950s Japan: The Niijima Gakuen Junior College Research Building

In a quiet residential neighborhood of Takasaki City in Gunma Prefecture stands an unusual structure that looks more like a giant white drum than a traditional Japanese school. Three stories of smooth reinforced concrete curve around in a perfect circle, crowned by a small cylindrical tower at the top. This is the Niijima Gakuen Junior College Research Building — formerly the circular schoolhouse of Takasaki Municipal Girls' High School — a registered tangible cultural property and the last surviving "circular school" in Gunma Prefecture.

For visitors interested in modern architecture, post-war Japanese history, or simply unusual buildings, this 1956 design by architect Kanao Sakamoto offers a window into a remarkable but largely forgotten chapter of Japanese architectural experimentation. Around 100 circular schoolhouses were built across Japan in the 1950s and 1960s, but only about 30 remain today, making each surviving example increasingly precious.

What Is This Building?

The building is a three-story, reinforced concrete structure with a building area of 491 square meters. From the outside, it appears as a near-perfect cylinder, with a smaller cylindrical rooftop tower (used to house ventilation and circulation features) crowning the design.

Step inside, and the layout is just as striking. At the very heart of the building is a wide central hall with a spiral staircase rising through all three floors. Around this central core, each floor is divided into six pie-slice sections: five fan-shaped classrooms plus one section containing the stairs and restrooms. The result is a building where the corridor essentially disappears — students moved directly from the central hall into their classrooms, an arrangement that the architect believed was both economical and pedagogically efficient.

Today the building is no longer used as a high school. After the original Takasaki Municipal Girls' High School relocated in 1981, the educational foundation Niijima Gakuen took over the site, and in 1983 opened the Niijima Gakuen Women's Junior College (now coeducational and known as Niijima Gakuen Junior College). The circular building was repurposed as a research building, where each individual faculty member maintains a private research office in one of the fan-shaped rooms.

The Architect and His Bold Vision

Kanao Sakamoto: Champion of "Pure Functionalism"

The building's architect, Kanao Sakamoto (1911–1987), is one of the most fascinating figures in 20th-century Japanese architecture. A graduate of Tokyo Institute of Technology — where he had already designed a circular airfield as his graduation project — Sakamoto worked at the predecessor of today's Taisei Corporation before founding his own firm, the Architectural Comprehensive Planning Institute, in 1954.

Sakamoto championed a design philosophy he called "pure functionalism." His core conviction was that buildings should be made as economically as possible — achieving their purpose with the minimum space, materials, and maintenance costs. For him, the circular plan was not a stylistic flourish but a logical consequence of this philosophy. A circle, after all, encloses the maximum floor area with the minimum length of exterior wall.

The Circular School Boom

Sakamoto's first circular schools were built in 1954, and the design quickly attracted nationwide attention. Newspapers and even foreign media took note; reporters reportedly arrived by helicopter to photograph one early example. Throughout the late 1950s, Sakamoto and his imitators built over a hundred circular schools across Japan, from Hokkaido in the north to Kagoshima in the south. The Takasaki building, completed in 1956, dates from this peak period and is among Sakamoto's early works in the genre.

The boom did not last. The fan-shaped classrooms were difficult to fill efficiently with rectangular desks, expansion was nearly impossible without disrupting the design, and the form did not adapt well to the surging student populations of Japan's baby boom. By the late 1960s, no new circular schools were being built, and the existing ones gradually fell to demolition. Each surviving example is therefore both an architectural curiosity and a poignant survivor.

Why It Was Designated a Cultural Property

On May 10, 2018, the building was officially registered as a Registered Tangible Cultural Property (Building) by Japan's Agency for Cultural Affairs. The designation recognizes several layers of significance.

First, the building represents an early and intact example of Sakamoto Kanao's circular school design — a distinctly Japanese architectural experiment that briefly captured the imagination of the country in the 1950s. As one of his earlier works, the Takasaki building shows the design at a formative stage, when ideas about how to organize the interior were still being refined.

Second, it is the only surviving circular schoolhouse in Gunma Prefecture, where similar buildings once stood at other schools (including a now-demolished circular schoolhouse at Isesaki Municipal Girls' High School from 1958). Its survival in continuous educational use — first as a high school, now as a college research building — is itself remarkable.

Third, the building has become a beloved local landmark. Generations of high school students passed through its corridors before its conversion, and it continues to symbolize Niijima Gakuen Junior College today. The cultural property designation honors not just the architecture, but the building's role as a shared community memory.

Highlights and What to Look For

The Cylindrical Silhouette

The first impression — and arguably the most photogenic feature — is simply the building's overall form. Most schools in Japan are long, rectangular blocks of classrooms; this is a perfect drum. The smaller cylindrical tower on the roof creates a stacked, telescoping effect that reads almost like a piece of mid-century industrial design rendered at architectural scale.

The Spiral Staircase

The interior centerpiece is the spiral staircase that rises through the building's central core. The staircase is not just functional — it is the spatial heart of the design, around which all the classrooms orbit. Visitors lucky enough to glimpse the interior often remark on how unexpectedly playful and sculptural this central space feels.

The Fan-Shaped Rooms

The five wedge-shaped rooms on each floor are now used as individual faculty research offices, but their unusual geometry remains immediately apparent. The walls converge toward the center of the building, while the outer wall — slightly curved — runs along the perimeter. The original classrooms placed blackboards on the inner (narrow) end of the wedge so that students faced inward, with the teacher able to take in the entire class at a glance.

Greek Lettering on Campus

While exploring the campus around the circular building, visitors should look for the Greek inscription on the wall of another campus building. Niijima Gakuen's educational motto — "Truth, Justice, Peace" — is rendered in ancient Greek on the second-floor exterior, reflecting the school's Christian humanist heritage rooted in the ideals of Joseph Hardy Neesima (Niijima Jo, 1843–1890), the founder of Doshisha University in Kyoto.

How to Visit

The building stands on the active campus of Niijima Gakuen Junior College and currently functions as a working faculty research building. It is not a museum, and the interior is generally not open to the casual visitor. However, the exterior can be admired from public vantage points around the campus, and the cylindrical form is striking even from a distance.

Visitors interested in seeing the building should approach respectfully, keeping in mind that this is an active educational institution. Open campus events — particularly those held for prospective students — sometimes offer the best opportunity to see the campus and its landmark building up close. Inquiries about specific viewing arrangements should be directed to the college's admissions and public relations office in advance.

The closest station is Kita-Takasaki Station on the JR Shin'etsu Line, about a five- to eight-minute walk away. From the larger Takasaki Station — a major Shinkansen hub roughly an hour from Tokyo — the campus can be reached in about 10 minutes by Joshin Bus to the "Niijima Tandai-mae" stop, or in around 15 minutes on foot.

Things to Do Nearby

Takasaki is best known to travelers as the home of the Takasaki Daruma — the round, red, eyebrow-arched good-luck dolls that are produced here in greater numbers than anywhere else in Japan. Around 80 percent of Japan's daruma dolls come from Takasaki workshops, and several of them welcome visitors for painting experiences.

Within a short trip of the circular schoolhouse, visitors can also explore Shorinzan Daruma-ji Temple, the spiritual home of the daruma tradition, where a famous market is held every January. The Takasaki White Robe Kannon — a 41.8-meter-tall white statue of the goddess of mercy completed in 1936 — looks out over the city from a wooded hilltop and offers panoramic views from inside. The Takasaki Castle Ruins Park, with its preserved corner turret and gate, provides a green space for cherry blossom season. The Takasaki City Art Museum and the adjacent former Inoue Fusaichiro Residence — a 1952 home in the style of Antonin Raymond — are also within easy reach for those interested in modern architecture and art.