His uncle, Momotaro Yanagida, was mayor of the City of Moji (Fukuoka Prefecture) and a member of the House of Representatives.

During his time at the ministry, Yamamoto studied abroad for two years at Cornell University's Samuel Curtis Johnson Graduate School of Management, where he acquired his MBA in 1975.

[2] Yamamoto initially ran under the LDP in the general election of 1990 in the fourth precinct of Fukuoka, but could barely not secure any of the four allotted lower house seats.

For the next general election of 2000, he once again ran in the 11th precinct, but this time as a conservative independent, and again garnered more votes than Nakinishi and Takeda.

Takeda went on to rejoin the LDP in 2004, but was rejected the party position for the 2005 election due to his opposition of the Postal Service Privatization Act.

[4][5] He also advocated for basic allowances and various public-works projects for low-income earners (among other economic policies) through a revised budget that matched the tax increase.

After citing unexpected economic indicators, however, Yamamoto proposed a postponement of further consumption tax increases and concomitant policies in October of the same year.