Short answers, pulled from the story.
Educators Tsunesaburō Makiguchi and Jōsei Toda established the group on the 18th of November 1930. The organization began as a society for value-creating education before evolving into a religious movement based on Nichiren Buddhism.
Authorities arrested leaders including Tsunesaburō Makiguchi and Jōsei Toda in 1942 under the Peace Preservation Law and lèse-majesté charges. They faced prosecution for denying the Emperor's divinity and insisting that the emperor was an ordinary man who made mistakes like anyone else.
Soka Gakkai reported reaching 6.2 million families by 1967. This growth occurred after Daisaku Ikeda took over as president in 1960 and expanded the organization rapidly both inside and outside Japan.
Nichiren Shōshū excommunicated Soka Gakkai and Soka Gakkai International on the 28th of November 1991 due to doctrinal conflicts. The group subsequently rewrote its bylaws in 2014 to reflect no relationship with Nichiren Shoshu or its doctrine.
Daisaku Ikeda founded the Komeito party in 1964 which became the third largest political party in Japan. The New Komeito Party entered a coalition agreement with the Liberal Democratic Party in 1999 before the coalition dissolved in 2025.