Jun Ishiwara or Atsushi Ishihara (石原 純; January 15, 1881 – January 19, 1947) was a Japanese theoretical physicist, known for his works on the electronic theory of metals, the theory of relativity and quantum theory. Being the only Japanese scientist who made an original contribution to the old quantum theory, in 1915, independently of other scientists, he formulated quantization rules for systems with several degrees of freedom.
Source: “Jun Ishiwara”, English Wikipedia (CC BY-SA 4.0), excerpt