She graduated from Awa High School in 1984 and gained a bachelor's degree in education from Chiba University in 1988.

[1] After graduating university Aoki was active as a singer-songwriter, releasing a total of six singles between 1989 and 1998, and an album titled Doko-e Iku-no (何処へ行くの, Where [will you] go?)

Aoki's comparatively low margin of defeat meant she gained the DPJ's final seat in block.

[3] In the 2005 general election Aoki again contested the Chiba 12th district against Hamada, this time losing by more than 50,000 votes[4] and failing to retain her seat in the proportional representation block.

[12] In July 2009, whilst still in the second year of her six-year term as a Councillor, Aoki nominated as a candidate for the Tokyo 12th district in the August 2009 general election, thereby automatically losing her seat in the House of Councillors; she was replaced by fellow DPJ candidate Tadashi Hirono.

[13] In the election Aoki defeated Akihiro Ota, the incumbent member and leader of the Komeito party, by more than 10,000 votes.

[20] On 2 July 2012 Aoki was one of fifty DPJ Diet members, led by Ozawa, to resign from the party after Prime Minister Yoshihiko Noda publicly announced as policy a plan to increase the national consumption tax.

[21] A week later 37 members including Aoki and Ozawa were officially expelled from the DPJ for voting against the tax bills.

[20] In the December 2012 general election which removed the DPJ from power, Aoki contested the Tokyo 12th district as a Tomorrow Party candidate, losing to Ota by 47,000 votes.