Yamasaki Masaki, a six-term Liberal Democratic Party member of the House of Councillors who served as its president, died on Friday at 84, Sankei Shimbun reported, citing a party official.
He represented the Fukui electoral district. Before entering national politics he served in the Fukui prefectural assembly.
Yamasaki first won a seat in the 1992 upper house election and was serving his sixth term at the time of his death.
Posts across party and government
He served as deputy chief cabinet secretary and as the LDP's upper house secretary-general, among other posts.
The House of Councillors, Japan's upper chamber, gives each prefecture its own electoral district, and Fukui is one of the smaller ones. Yamasaki held his seat through six national elections.