SoftBank and OpenAI held a groundbreaking ceremony Monday for Stargate Japan Phase One, a data-center campus near Osaka projected to house 200,000 GPUs by 2029. The partners valued the first phase at $15 billion, with Japanese government-backed lenders providing concessional financing for power infrastructure.
Prime Minister Shigeru Ishiba said the project advances national AI sovereignty goals while keeping model weights for government clients onshore. OpenAI will operate training and inference services; SoftBank retains sales rights across Southeast Asia.
Energy Plan
Developers signed a 15-year power purchase agreement blending restarted nuclear units in Fukui Prefecture with offshore wind contracts. Environmental groups questioned transparency on cooling water discharge volumes; operators pledged quarterly environmental reporting.
Workforce
SoftBank committed to training 8,000 technicians through partnerships with Osaka University and Ritsumeikan. Union organizers sought guarantees that facility jobs would not be outsourced to temporary staffing agencies.
Geopolitical Context
The United States welcomed the project as diversification away from Taiwan-centric supply chains. Chinese state media criticized Japan for deepening dependence on American AI stacks. South Korean conglomerates said they are evaluating comparable sovereign compute partnerships with domestic chip makers.
Timeline
Phase One targets operational status in late 2028, with a 50,000-GPU tranche available to enterprise customers in 2027 if construction stays on schedule.
