On August 31, 1937, during the 1937 Fall season, Dai Tokyo changed its name to Lion after the team was bought by Lion Toothpaste and Komajiro Tamura. Lion reportably payed for half of the team's salaries, 800 yen, in return for the team's naming rights. Lion finished as high a sixth in both the 1937 and 1938 Fall seasons, but finished in second-to-last or last place in its four other seasons. When the Japan Baseball League outlawed English nicknames late in the 1940 season, Tamura refused to change the team's name during the season due to the team's sponsorship contract with Lion by insisted that "Lion" is Japanese. The team finished the season as Lion before changing its name to Asahi in January 1941 after the team's sponsorship contract ended.
1937 (midseason) - 1940