The Japan Little League Baseball Association was founded in 1964 with the aim of fostering the healthy development of Japanese children through hardball baseball. Mitsui has supported the activities of the Little League for children up to age 12 since 1970.
Nationwide, the Little League encompasses 891 teams in 246 leagues and 12 regional associations, making it the second largest such organization in the world after its United States counterpart. The Little League World Series, held every year in the United States, was won in 2015 by the Tokyo-Kitasuna League of the Tokyo Association, the fourth time a member of the Little League has won the world title.