Tamura was born on 4 July 1965, in Komoro, Nagano Prefecture, to parents who owned a stationery shop.

[3] After she graduated, she took full time employment with the Democratic Youth League of Japan, organizing anti-war protests and pro-peace rallies.

[8] She criticized former Prime Minister Shinzo Abe's female cabinet picks, saying that they were performative instead of advancing women's empowerment.

Tamura's selection has been viewed by some as an attempt to repair the Communist Party's image in this scandal's wake.

[13] Tamura stood for the October 2024 House of Representatives election as the top candidate on the Communist Party list for the Tokyo proportional representation block.