Ota also participated in changes in the Commercial Law in the late 1990s and realignment of government ministries and agencies in 2001.

[4] On 1 August 2008, Yasuo Fukuda named Ota as the Minister of Agriculture, Forestry and Fisheries in the cabinet list.

[5] However, he resigned the post on 19 September 2008, following a scandal over tainted rice (汚染米 or 事故米穀, Osenmai or Jikobeikoku).

[6] He stated: "I met with Prime Minister Fukuda and told him my decision to resign, considering the seriousness of the tainted rice problem for the society."

The rice, tainted with pesticide methamidophos and mould, was for industrial uses only, but was resold, used and served to make lunches for thousands of schoolchildren and nursing home patients.