She graduated from the University of Tokyo with a Bachelor of Laws. In 1972 Sakamoto joined the Ministry of Labor (now part of Ministry of Health, Labour and Welfare), serving in the Women Labourers' section of the Women's Bureau. She later transferred to the Employment Security Bureau, where she served as head of the policy section for employment of the disabled. In 1996 Sakamoto was seconded to the post of Vice-Governor of Shizuoka Prefecture, becoming the first woman vice-governor of the prefecture. She served in that role until 1999. Following her term as Vice-Governor, Sakamoto returned to the Ministry and served as an Assistant Secretary to the Minister until 2001, then as head of the Occupational Health and Safety Department. Sakamoto finally served as head of the Human Resources Development Bureau from 2002 until her resignation from the ministry in 2004. Political career In July 2004 Sakamoto was elected to the House of Councillors as a Liberal Democratic Party candidate in the Shizuoka at-large district. Sakamoto received the most votes in a five-person contest for two seats, defeating incumbent Councillors  of the LDP and  of the Democratic Party. Upon entering the Diet Sakamoto served on the House's Health, Welfare and Labour Committee and later in July 2007 was appointed as a director of the House's Budget Committee.
She graduated from the University of Tokyo with a Bachelor of Laws. In 1972 Sakamoto joined the Ministry of Labor (now part of Ministry of Health, Labour and Welfare), serving in the Women Labourers' section of the Women's Bureau. She later transferred to the Employment Security Bureau, where she served as head of the policy section for employment of the disabled. In 1996 Sakamoto was seconded to the post of Vice-Governor of Shizuoka Prefecture, becoming the first woman vice-governor of the prefecture. She served in that role until 1999. Following him term as Vice-Governor, Sakamoto returned to the Ministry and served as an Assistant Secretary to the Minister until 2001, then as head of the Occupational Health and Safety Department. Sakamoto finally served as head of the Human Resources Development Bureau from 2002 until her resignation from the ministry in 2004. Political career
 In July 2004 Sakamoto was elected to the House of Councillors as a Liberal Democratic Party candidate in the Shizuoka at-large district. Sakamoto received the most votes in a five-person contest for two seats, defeating incumbent Councillors of the LDP and of the Democratic Party. Upon entering the Diet Sakamoto served on the House's Health, Welfare and Labour Committee and later in July 2007 was appointed as a director of the House's Budget Committee.