NTT Data Group is in the final stages of talks to build a data center in Osaka Prefecture for Anthropic, in what would be the U.S. AI developer's first dedicated facility in Japan. The project could draw up to 500 MW and cost as much as ¥1 trillion, abou
Architectural rendering of an NTT Kansai/Keihanna data center campus directly from NTT's press releases.t $6.3 billion, Nikkei Asia reported on Oct. 13. Neither company has confirmed the plan.
The site would sit on the southern coast of Osaka Prefecture. Construction alone could reach ¥1 trillion, and adding a large fleet of advanced GPUs for AI training and inference could push total investment into the several-trillion-yen range, according to Nikkei. Partial operations could begin as early as 2028, with the two sides aiming to sign an agreement by the end of NTT's fiscal 2026, which closes March 31, 2027.
Power is the binding constraint. A 500 MW grid connection would take years to secure, so the project is expected to lean first on on-site generation and fuel cells, The Next Web reported. Both NTT Data and Anthropic declined to comment, Reuters reported.
Built at that scale, the campus would rank among the largest single data centers in Japan.
NTT is not starting from scratch. NTT Data ranks third among the world's data center operators by market share and runs more than 1,600 MW across the United States, Europe and Asia. In its home market, the company plans to grow domestic IT power from roughly 300 MW to about 1 GW by fiscal 2033, w.media reported.
Anthropic's Japan presence is widening too. In May, Hitachi agreed to roll out the Claude models across its workforce of about 290,000 people.
Osaka is already drawing new capacity. This month Digital Realty's MC Digital Realty joint venture started KIX15, a 24 MW building at its KIX campus in Ibaraki City. Baxtel tracks 250 data center facilities in Japan operated by 51 providers; NTT accounts for 23 of them, and the country's largest site, Tokyo Chuo Center (CC1 & CC2), is rated at 130 MW.
The reported deal points to a pattern reshaping AI infrastructure: a model developer anchoring a purpose-built campus rather than leasing colocation, and a national carrier building it. Grid power in Japan takes years to land, which is why NTT would lean on on-site generation from the start. In a market where speed to power decides who builds, that choice is the one to watch.
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