[1][2] Takeiri joined Soka Gakkai after World War II had ended, having formerly been a worker at Ina Junior High School as well as Japanese National Railways (now JR East).

Takeiri was first elected to public office as a Soka Gakkai-endorsed independent candidate in April 1959 as a member of the assembly for Tokyo's Bunkyō Ward.

[5] On 21 September 1971, Takeiri was stabbed with a knife in front of Komeito headquarters by a thug and suffered from heavy injuries for the next three months.

In July 1972, Takeiri flew to Beijing and met Zhou Enlai, and thereafter returned to report back to Tanaka and then-Foreign Minister Masayoshi Ōhira.

[8] In 1974, Soka Gakkai and the Japanese Communist Party secretly agreed to a ten-year accord of reconciliation, and, in addition, Kenji Miyamoto and Daisaku Ikeda had held multiple meetings with each other in that year.

[13][14][15][16][17] Further controversy ensued when a 2006 internal investigation by Komeito resulted in an accusation that Takeiri embezzled party money in 1986 so as to purchase a ring for his wife, a claim which was bolstered in the official Soka Gakkai newspaper Seikyo Shimbun.