The Enigma of the Prism House

The Quest for a Puzzling Work by Shinohara

Christian Dehli

This record of a voyage of discovery to one of Shinohara’s least well-documented houses exemplifies the fascination of his buildings. Our author’s report recounts the persistence required to unravel the mystery of Shinohara.

I first came across the work of Kazuo Shinohara while serving an internship in Tokyo in 2005. His frequently small single-family houses with their very unusual spaces and spatial sequences fascinated me, particularly those of his so-called Third Style. In leafing through his books I found myself lingering repeatedly at one particular work. This house with its rather curious name of Prism House was documented in rudimentary fashion only – plans, an exterior photo and two interior shots.

Even the basic description irritated me a little: “The basic shell is a prism 10.9 meters long, the vertical section of which is an isosceles right triangle with a base of 7.6 meters and a hypotenuse of 10.8 meters. The prism, like the cube, is a primary geometrical form …”1 This feels more like the description of a pure geometric solid than an architectural object. Shinohara reflected on mathematical and architectural issues in almost the same way.2 It also surprised me that the publication contained a number of inconsistencies: plans that did not match and a photo mistakenly rotated at 90-degrees. This was strange, as Shinohara supervised the publication of his houses with extreme care.3

In 2013 together with a graphic designer friend I designed a Prism House booklet. I redrew the plans and scrutinized its overall spatial impression by means of a small model built on the basis of details I knew. This house simply refused to let go of me.


In the 2G Casas/ Houses4 of 2011 devoted to Shinohara’s houses mention is made of a drawings archive at Tokyo Institute of Technology (Tokyo Tech), which I had previously not known about. I asked a friend to convey my Prism House booklet to its curator, Professor Shin-ichi Okuyama, together with a request for further information. He offered to show me the working drawings for the house on my next visit to Tokyo.

With the goal of finding the house within three weeks I booked a flight to Japan, and in mid-July 2014 I met Professor Okuyama for the first time. My obsession with the Prism House met with little understanding, as it is not considered a canonical work and cannot easily be attributed to a single style. Shinohara himself described it as “an intermezzo between the Second and the Third Styles“5, and on this account Professor Okuyama thus refers to it as mysterious. Nonetheless, I was shown the original working drawings, a few hand-drawn sketches and several photographs. But there was no information about the original location of the house. I was told, however, that the project architect responsible for its construction now taught at Tōkyō Zokei University and also maintains his own office. Towards the end of my stay I was able to meet him at Tokyo Tech’s Centennial Hall.

He believed that Shinohara had earlier hoped to make use of a triangular form in another project. As that house was never built, the sketch vanished into a drawer until the commission for the Prism House arrived. He also explained that the client had been Setsu Asakura. She died in spring of 2014 at the age of 91, having been one of the most famous stage designers in Japan. Enquiries produced the information that a meeting with her film-director husband, Yukio Tomizawa, would be impossible owing to ill health.

For its part, Tokyo Tech continues unswervingly to observe Shinohara’s own policy: when a house was complete it would be photographed and handed over to the client; later contacts or visits were and are excluded. On account of the professional position of the clients neither the Asakura House in Tokyo nor the Prism House were published at the time they were built. Indeed, like the Asakura-Tomizawas, many of Shinohara’s clients and in particular those for the smaller houses were creative people: film makers, painters, artists or poets. As the Prism House was built more than forty years ago the site architect, whom I met and who had been responsible for the project was no longer able to recall its exact location. By chance, during our conversation mention was made of an ostensible TV-advertising spot for a Japanese skin-care product. This had supposedly been filmed inside the Prism House at the end of the 1980s but it was said that Shinohara managed to have the footage withdrawn from circulation.


A short time later, disappointed and uncertain whether the house still existed or even where it had stood, I returned home. Once back in Switzerland, I combed the Internet looking for the advertising spot and once more tried to make direct contact with the client. A tip from the Japanese cultural attaché in Bern that I might write to documentary film maker Linda Hoaglund proved invaluable. She had conducted an interview with the Asakura-Tomizawa couple and was able to confirm that the Tomizawa famiy was still living in the Asakura House.

After innumerable unsuccessful mails to Japanese cosmetics manufacturers I found an advertising spot on YouTube in which the interior of the Prism House can be seen for one second.

With this at the back of my mind, I again booked a flight to Japan. At the start of December 2014 I sent Mr Tomizawa a letter requesting a meeting. Via the Internet I anxiously followed the letter’s path to Japan and was relieved when I saw that it had arrived at its destination. But no answer ever came.

As I knew that the Prism House had been built in Yamanashi Prefecture, in the village of Yamanakako, just about a hundred kilometres southwest of Tokyo, I searched this region on Google Earth. The area of the Fuji Five Lakes at the foot of Mount Fuji is still a favourite retreat for people from Tokyo who wish to escape the hot, humid summers of the city. At the beginning of the 1970s, a number of well-known cultural figures were building holiday houses in these still untouched woods. So at the time the Prism House was built, trees already towered over it. Therefore, I had little hope of locating it today on a satellite image. But two bold strokes of good luck helped me discover the exact location. The grandmother of a friend of a friend confirmed that the house still belonged to the Asakura-Tomizawas. She mentioned that it was now part of a private holiday compound equipped with access control, video surveillance and other barriers. Meanwhile, a Japanese friend inspected the local property register, discovering that the house I had spotted on the computer screen predated 1981.

Danger: bears

Immediately after arriving in Tokyo I travelled by bus to Yamanakako. The next day I started my search. To avoid the access control of the now gated community I chose a route over a mountain ridge and through steep, dense woodland. Somewhat nervous on account of signs proclaiming: “DANGER bears!” and because of my status as a trespasser, I nonetheless eventually managed to reach the house. The first glance confirmed fears I had experienced when culling the satellite images. Façade and roof were renovated and new windows had been added. Moreover, next door stood a second house. Yet despite the renovation of Prism House, its external condition was better than I had hoped. I was not able to judge the interior, as all curtains were drawn.

Was that going to be it? I was unsatisfied leaving the house without having seen the interior. Back in Tōkyō, shortly after the start of the New Year I rang the doorbell at the Asakura House in town. A personal assistant to the Asakura-Tomizawa family, who had worked for them for many years, opened the door and explained to me that his employer was now living in a nursing home and could not possibly grant an interview. After two telephone calls and a short wait I was however able to speak with the couple’s daughter. Totally unexpectedly and in a very direct manner, she asked me if I would like to visit the Prism House. Of course I replied in the affirmative! She apologised in advance for any possible untidiness as she had not been there for quite some time. After a further telephone call the key was made available at Yamanakako and two days later I entered the house — this time as an invited guest. Given the long history of my quest, I never imagined that it would end in such an uncomplicated way.

Fiction and Reality

The couple’s daughter explained further that Shinohara had been a good friend of the family and had on several occasions worked together with Asakura.6 He had been commissioned to design their house at Yamanakako, she said, because her parents were so satisfied with the larger house he had built for them in Tokyo. Both had immediately liked the proposed triangular design. Yet, as they grew older the couple felt a need for greater comfort. Not only was the original house renovated but also a new house was erected adjacent to the Prism House.

Before leaving, and out of pure curiosity, I then asked the daughter if she knew anything about the advertising spot. She and the assistant, who was also there, had never heard about it and had to laugh when I played the video. Both noticed a number of things that were not right: the floor was never yellow nor had the stairs ever been painted white. Finally, a structural element articulating the space that ought to have been there was missing, despite the camera perspective being right. The spot had in fact been shot on a film set apparently based on the interior of the Prism House. Even Shinohara himself seems to have been deceived by the short film sequence – or perhaps not.

Christian Dehli (1980) studied architecture at the ETHZ and now maintains an architecture design office in Zurich.  

1 Kazuo Shinohara, Kazuo Shinohara 2. 11 Houses and Architectural Theory, Tōkyō 1976, p.161.

2 Hans Ulrich Obrist, Hans Ulrich Obrist Interviews Volume 2, Milan 2010, p. 223.

3 David B. Stewart, Shin-Ichi Okuyama and Taishin Shiozaki, Editor’s Note, in: Gustavo Gili (2G), N.58/59 Kazuo Shinohara Houses, Barcelona 2011, p. 51.

4 Gustavo Gili (2G), N.58/59 Kazuo Shinohara Houses, Barcelona 2011

5 Kazuo Shinohara, A Program for the «Fourth Space», in: The Japan Architect, JA 353 September 1986, Tōkyō 1986, p. 32.

6 The Japan Architect, February 1963, Tōkyō 1963, p. 76.

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