The dominant image of contemporary architecture in Japan is one of serene simplicity: spaces that are light, bright and weightless, in which structure and materiality are reduced to the minimum.

The ethereal works of the architectural firm SANAA, designed by Kazuyo Sejima and Ryue Nishizawa, are the best known examples of this tendency, which holds a large number of younger architects, both here and abroad, in its thrall. But the true father of this approach is Toyo Ito, Sejima’s early mentor.

Ito spent the last decades of the 20th century exploring the idea of an architecture for the “virtual” body — the parallel self that lives on the incessant diet of electronic information in the modern metropolis. He once famously said that contemporary man was a “Tarzan who lives in a forest of media,” and his architecture should be a form of “media-clothing.”

A diaphanous, weightless architecture was the result, a direction that Sejima and her disciples have been steadily extending. In this decade, however, Ito has decisively swerved away from this path to re-engage the forceful physicality of the structural and material dimensions of architecture. He has returned to the “real.”

The exhilarating results of this shift are on show at the Tokyo Opera City Art Gallery, in an exhibition entitled “Toyo Ito: The ‘New Real’ in Architecture.” In addition to a detailed chronology of his works from earlier days, nine projects are shown, from the Sendai Mediatheque, which opened at the turn of the millennium, to last year’s winning design for the Taichung Metropolitan Opera House Competition in Taiwan. Presenting his projects in an engaging way that reveals a compelling architectural vision, it is a stunning show that has been executed with rigor and verve.

The Taichung project is the undisputed star of the show, with the entire entrance hall grandly devoted to it. An enormous model nearly 4-m long wows onlookers with its voluptuousness and audacity. The design resembles an enlarged block of spongy bone marrow, involuted and porous, into which three large performance spaces are inserted almost as an afterthought. It is a work of tremendous ambition, the equivalent in our own time to that of the Sydney Opera house. If Taichung pulls it off, it will likely do for that city what the sails by the Danish architect Jorn Utzon did for Sydney.

The challenge of mounting an exhibition of architecture in a gallery is that the actual architecture itself is absent, with models, photographs, plans and other representations — which are often understood only by specialists — standing in for the real thing. For this show, devoted as it is to the “real” and held in a mainstream gallery, particular efforts were made to overcome this limitation.

Ito says children make the best critics for this task: “I asked myself what would an exhibition of architecture that children would enjoy be like?”

The answer is to be found in the main room, which forms the heart of the show. A white floor, undulating like a billowing carpet, invites visitors to step out of their shoes and into a generous space — one has the uncanny feeling of stepping into Ito’s brain. Floating before you are large-scale models of Ito’s recent projects, organic forms which are like husks, skeletons and shells from some hitherto-unknown natural history. Extending to the high ceiling are full-scale technical drawings.

At the end of the room, the branching concrete limbs of the facade of the TODS building in Omotesando are presented in a sequence that moves from drawing to reinforcing cage to wooden-form work to a rebuilt copy in finished concrete with inset glass. When I visited, the children there were loving it, gazing in wonder at the strange constructions and running about the rippling floor, inviting the adults to share in their delight.

Ito feels this bodily pleasure which is experienced via architecture is being lost in the wholesale embrace of the virtual.

“In little over 10 years, mobile phone and Internet technology have changed things radically. I think that, without doubt, people, especially young people, have lost a kind of ‘rawness,’ a nama feeling. I had originally hoped that by engaging with virtual worlds, such as when playing computer games, a new and interesting kind of sensibility would develop among people. However, in truth, I soon began to feel a sense of betrayal. I concluded that the more this virtualization occurs, the greater the need for the primitive body.”

The experience of building the Sendai Mediatheque catalyzed Ito’s swerve toward the real. As the original image of translucent tubes swaying like seaweed in a warm ocean of information took form as massive structural elements in steel, Ito suddenly grasped what he calls the “power of substance.”

“During the process of construction I remember going to see the site and looking out over that primal scene, and thinking: ‘This, after all, is architecture!’ “

The recovery of the “real” that is so new for Ito and his successors suggests a yearning to reconnect to the sources of the architect’s art: material, structure, nature and, significantly, people. If the children are right, then the feeling is mutual.