NTT Commences Photonics-Driven Urban Development powered by IOWN, starting in Hibiya
~NTT to relocate its headquarters to Hibiya, the birthplace of the NTT Group, in 2031~

TOKYO - December 8, 2025 - NTT, Inc. (Headquarters: Chiyoda-ku, Tokyo; President and CEO: Akira Shimada; hereinafter "NTT"), NTT Urban Solutions, Inc. (Headquarters: Chiyoda-ku, Tokyo; President and CEO: Kou Ikeda; hereinafter "NTT Urban Solutions"), and NTT Urban Development Corporation (Headquarters: Chiyoda-ku, Tokyo; President and CEO: Kou Ikeda; hereinafter "NTT Urban Development") will begin Photonics-Driven Urban Development powered by IOWN, a new urban development concept enabled by IOWN^*1, a next-generation information and communications platform spearheaded by NTT. This Initiative aims to create a city that evolves in step with technological advancement.

The first phase of the Initiative will be implemented at the NTT Hibiya Tower, which is being developed in Chiyoda-ku, Tokyo, with NTT Urban Development and TEPCO Power Grid, Incorporated serving as project owners. Scheduled for completion in late October 2031, NTT Hibiya Tower will play a key role in realizing the next-generation smart city vision outlined under the Uchisaiwaicho 1-Chome District^*2.

Hibiya has long been a place of deep significance since Nippon Telegraph and Telephone Public Corporation (now NTT) established its headquarters there in 1961. NTT plans to relocate its headquarters to NTT Hibiya Tower and, by bringing together the technological capabilities and expertise cultivated across the NTT Group^*3, aims to deliver unprecedented new value and achieve remarkable ultra-low power consumption. Through co-creation with partner companies, the Initiative seeks to integrate diverse insights and cutting-edge technologies to help build a more sustainable, people-centric, and vibrant society.

Rendering of the Completed Uchisaiwaicho 1-Chome District [1]

Background

Japan currently faces a range of serious societal challenges, including labor shortages driven by a declining birthrate and aging population, global warming caused by climate change, and increasingly frequent natural disasters. Addressing these issues to build a sustainable society has become an urgent priority. At the same time, while the growing adoption of AI, robotics, and mobility technologies is enriching daily life, the sharp rise in power consumption associated with these advancements is a major concern.

To confront these challenges, the next-generation information and communications platform IOWN is designed to process massive volumes of data with high capacity, low latency, and low power consumption. By supporting society through this advanced infrastructure, IOWN enables solutions across a wide range of fields, including operational efficiency and automation for enterprises, disaster and climate prediction, and automated control of infrastructure and the environment. In the field of urban development as well, the use of photonics and other advanced technologies aims to enhance quality of life and contribute to the creation of a safer, more secure, and more sustainable society.

Overview

Through the implementation of IOWN and other advanced technologies, together with co-creation with partner companies, the Initiative aims to deliver the following value.

■ New Business and Innovation

With IOWN implemented throughout the tower, real-time collaboration with partners around the world becomes possible, supporting innovative and creative corporate activities. In addition to spatial transmission enabled by IOWN, the use of services that integrate the latest technologies, such as the NTT-developed LLM "tsuzumi 2"^*4 and the large-scale AI collaboration technology "AI Constellation"^*5, will enhance efficiency and productivity for both organizations and office workers, facilitating cross-border co-creation.

Looking ahead, ideas generated during meetings will be easily transformed into models, and AI will serve multiple roles, such as advisor, concierge assisting with actions, or consultant retrieving and presenting relevant materials. By providing an environment that maximizes worker performance, the tower will support more creative and strategic activities than ever before.

Future Business Scenarios Unrestricted by Space or Time [2]

■ New Lifestyles and Entertainment Experiences

By connecting cities and districts around the world in real time through IOWN, entirely new lifestyle and entertainment experiences can be realized. At the lower levels of the tower, the large-scale passage and atrium space Cross Gate, seamlessly linked to Hibiya Park, will house an expansive indoor presentation and entertainment environment featuring integrated large LED displays across its walls and ceiling.

For example, the space can be used to host simultaneous announcements of new products and services to audiences across Japan and around the world, to support brand-building advertising initiatives, and to hold integrated events in collaboration with the retail facilities on the lower floors. Even outside of event periods, the space will function as a place for office workers and visitors to work and relax.

Looking ahead, by integrating technologies that create deeper immersion, such as Acoustic XR that blends NTT's real and virtual sound experiences, it will become possible to offer a wide range of experiences tailored to different purposes. These may include collaborative video galleries and art exhibitions linked with venues around the world, as well as interactive games and attractions.

Future Entertainment Concepts at the Cross Gate [3]
(Left: Virtual Aquarium / Right: Basketball Viewing Space Integrated with Other Venues)

■ Sustainability Through Ultra-Low Power Consumption

A sustainable society is supported through the creation of new value, including new businesses and lifestyles, enabled by the tower's building performance and advanced energy technologies. For the office floors, "ZEB Ready" is achieved by reducing the energy consumption required for a conventional building to less than 50 percent through design innovations in building specifications. In addition to the exceptional ultra-low power consumption enabled by photonic-electronic convergence devices, AI based on IOWN provides future prediction and optimal control of building systems. Through "Just Enough Energy,"^*6 which balances energy efficiency and occupant comfort, operational efficiency is maximized, resulting in a 10 to 20 percent reduction in CO₂ emissions. The use of clean energy further contributes to the realization of carbon neutrality.

Looking ahead, additional advancements will be pursued, including operational efficiency improvements enabled by emerging technologies such as optical quantum computing, as well as the exploration of next-generation clean energy sources such as hydrogen.

Initiatives Toward Carbon Neutrality

Future Developments

The Uchikanda 1-Chome district, where the tower will be located, is one of the core hubs in central Tokyo and is set to be transformed into a next-generation smart city that enables public–private collaboration and co-creation with companies and research institutions. Using the tower as a field for demonstration and implementation, the initiative aims to advance Photonics-Driven Urban Development powered by IOWN, delivering new value never seen before and achieving exceptional ultra-low power consumption. Insights gained through these efforts will be applied to surrounding areas, throughout Japan, and globally.

Location Map of the Surrounding Area

Roles of Each Company

Overview of the NTT Hibiya Tower

^＊Please note that the information in this release is current as of the date of announcement and is subject to change.

[Glossary]

^*1The IOWN (Innovative Optical and Wireless Network) concept refers to a network and information processing architecture, including end-user devices, designed to overcome the limitations of conventional infrastructure by leveraging photonics-centered innovative technologies. By providing ultra-high-speed, large-capacity communications and extensive computing resources based on all available information, the concept aims to optimize both individuals and the broader system, enabling the creation of an inclusive and diverse society. https://group.ntt/en/group/iown/

^*2One of the largest next-generation smart city projects in central Tokyo, featuring a total floor area of 1.1 million ㎡ (Tokyo Cross Park Vision) https://www.tokyo-cross-park.jp/

^*3Mainly referring to NTT, NTT Urban Solutions, and NTT Urban Development as outlined in the Roles of Each Company section.

^*4NTT's LLM tsuzumi 2 https://group.ntt/en/newsrelease/2025/10/20/251020a.html

^*5AI Constellation — a collaboration of diverse AIs https://www.rd.ntt/e/cds/ai-constellation/

^*6Just Enough Energy refers to an environmental management approach that balances energy efficiency and comfort by optimizing building controls in response to both indoor and outdoor conditions as well as operational needs. https://www.ntt-us.com/news/2022/12/news-221221-01.html

^[1]©Wire Collective

^[2]©PLP Architecture

^[3]©InPlace

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About NTT

NTT contributes to a sustainable society through the power of innovation. We are a leading global technology company providing services to consumers and businesses as a mobile operator, infrastructure, networks, applications, and consulting provider. Our offerings include digital business consulting, managed application services, workplace and cloud solutions, data center and edge computing, all supported by our deep global industry expertise. We are over $90B in revenue and 340,000 employees, with $3B in annual R&D investments. Our operations span across 70+ countries and regions, allowing us to serve clients in over 190 of them. We serve over 75% of Fortune Global 100 companies, thousands of other enterprise and government clients and millions of consumers.