This is the first in-depth scholarly treatment of the long-term development of U.S.-Japan baseball connections. Guthrie-Shimuzu studies the almost contemporaneous diffusion and popularization of baseball in the U.S., Hawaii, Japan, and east Asia under Japanese colonial rule. After the “opening” of Japan by Commodore Perry, the Meiji emperor began to engage the trans-Pacific world at roughly the same time as the United States and with energies and ambitions emblematic of rapidly industrializing and self reinventing societies. In its drive to modernize, the state recruited over 3000 foreign employees to assist the government in adopting western science and technology and building institutions to handle the demands of a complex modern society. Baseball was introduced to Japan by these “foreign employees,” and Japanese sent for study in the U.S. also picked up the game and were avid players upon their return home. Visiting warships fielded teams that played against local clubs and American teams—even Japanese American teams and Negro League teams, excluded from the major leagues—arranged tours to the island. By the 1930s,professional baseball was organized in Japan and even played throughout World War II.