[2] Katayama began his career at the agency of Home Affairs in April 1958.

[1] In January 2001, Katayama was named as the minister for public management, home affairs, posts and telecommunications.

[8] Katayama left the LDP when the party set an age limit of 70 for candidates in the House of Councillors proportional representation bloc election in 2010.

[10] He was reelected to the upper house for the fifth term in July 2010 for the Tachiagare Nippon.

[2] Next he became a member of the JPR, which was led jointly by Tōru Hashimoto and Shintaro Ishihara.