After graduating from Keio University in 1986 he worked as a journalist at Toyo Keizai before entering politics.
[1] Nishida was first elected to the House of Councillors in 2004 as the Komeito candidate in Saitama at-large district.
[2] In 2013, Nishida became secretary general for the Komeito caucus in the House of Councillors.
[1] From October 2018 he concurrently serves as Nishida head of the Komeito's tax panel.
[5][6] Nishida was appointed secretary general when Keiichi Ishii became party president in September 2024.