In parallel to the ITER Agreement, which established the ITER Organization, an agreement for complementary research and development called the Broader Approach was reached between the European Atomic Energy Community (Euratom) and the Japanese government.
Signed in February 2007, it established a framework for Japan to conduct research and development in support of ITER and the next-step device DEMO over a period of ten years.
Within the Broader Approach three projects were set into motion: a materials testing facility, a fusion energy research centre for advanced plasma experimentation and simulation, and an upgrade of the JT-60 tokamak in Japan to an advanced superconducting tokamak in order to contribute to the development of operating scenarios for ITER and to address key physics issues.
More on the Broader Approach
here.