He received a post-graduate Master of Public Policy degree from the John F. Kennedy School of Government in 1983, and worked as a management consultant for McKinsey & Company from 1984 to 1992.

He left the Cabinet in September 2014 to serve as Chairman of the Liberal Democratic Party Election Committee.

[3] As minister, he was sent as a special envoy to sign the Comprehensive and Progressive Agreement for Trans-Pacific Partnership in Santiago, Chile.

[7] Nikkei dubbed Motegi "Japan's 'Trump whisperer'" in recognition of his role in negotiating with US President Donald Trump and his administration.

In the trade package, British import tariffs are expected to reduce by up to 60% for Kobe beef, 31% for the Japanese chocolate snack Pocky, 22% for bluefin tuna, 13% for udon noodles, and 6% for soy sauce.

Motegi has been described as intensely passionate in his attempt to succeed Kishida as prime minister, and Kishida has dedicated a significant amount of time to disrupting him; with factionalism now in peril due to the 2023–2024 Japanese slush fund scandal, Motegi's future within the party has been described as possibly in danger.

Only a few cabinet posts were given to members of his faction, the Heisei Kenkyūkai; this was seen as punishment for Motegi backing Sanae Takaichi against Shigeru Ishiba in the second round of the LDP presidential election.