| June 2010 | Minister of Justice (Kan Cabinet) |
| September 2009 | Minister of Justice (Hatoyama Cabinet) |
| August 2007 | Chairperson, Executive Committee, Democratic Party of Japan (DPJ) |
| September 2006 | Chairperson, Public Relations Committee, DPJ |
| April 2006 | Next Minister of Justice, DPJ, "Next Cabinet" |
| September 2005 | Next Minister of Justice, DPJ, "Next Cabinet" |
| July 2004 | Elected as a Member of the House of Councillors (forth term) |
| December 2002 | Next Minister of Justice, DPJ, "Next Cabinet" |
| September 2001 | Vice President, DPJ |
| October 1999 | Next Minister of Internal Affairs and Communications/Gender Equality/Human Rights, DPJ, "Next Cabinet"
|
| July 1998 | Elected as a Member of the House of Councillors (third term) |
| January 1997 | Chairperson, the Special Committee for the Relocation of the National Diet and Related Organizations, House of Councillors |
| June 1996 | Chairperson, the Environment Special Committee, House of Councillors |
| July 1992 | Elected as a Member of the House of Councillors (second term) |
| August 1989 | Chairperson, the Audit Committee, House of Councillors |
| July 1986 | Elected for the first time as a Member of House of Councillors |
| April 1982 | Registered as Member of the Yokohama Bar Association |
