the league was established on february 5, 1936, as the japan occupational baseball league, with an initial complement of seven teams. three of the teams were based in tokyo, two in osaka, and two in nagoya. the league played fall and spring seasons in 1937 (c. 100-game schedule, in total) and 1938 (total 75-game schedule), adding one new team each year. it was renamed the japanese baseball league in 1939, playing a 96-game schedule. before the 1940 season, one of the founding teams, nagoya kinko (originally the nagoya golden dolphins), merged with the tokyo senators. the 1940 season featured a 104-game schedule.