This is a database of source documents that trace the footsteps of defence policy, consisting of the 'Defence Agency Historical Materials', a group of documents collected for the compilation of the Defence Agency History, and the 'Kubo Documents' and 'Ito Documents', personal documents of defence bureaucrats.

Part I: "Kubo Documents", "Ito Documents", Memoirs and Testimonies (1)
Focusing on materials from the 1960s and 1970s, the database contains personal documents of defence bureaucrats Takuya Kubo (former Administrative Vice-Minister of Defence) and Keiichi Ito (former Director-General of the Defence Bureau and Secretary-General of the National Defence Council).
In addition, some memoirs and testimonials by defence bureaucrats and Self-Defence Force officials in the 'Defence Agency Historical Materials' are also included. The main contents cover the period from the end of the war and rearmament to the 1970s.

Part II: Records of the Councillors’ Meetings, Bureau Meetings, and Joint Meetings of Senior Officials
This section contains the minutes and related records of internal meetings within the former Defense Agency, beginning with the minutes of the Councillors’ Meeting—the de facto final decision‑making body of the Agency. The collection covers materials from the Councillors’ Meeting starting in 1962 through the 1970s.

Part III: "Kubo Documents", "Ito Documents", Memoirs and Testimonies (2) 
Following Part I, this section includes the personal papers of Kubo Takuya and Ito Keiichi. In addition, it contains memoirs and testimonial records authored by Defense Agency officials and senior Self‑Defense Force officers, including the "Kato Yozo Diary". Also included are materials produced by the Institute for the Study of Historical Facts (established by Hattori Takushiro and others), the "Nagaishi Materials"—documents on demobilization and reparations left by Nagaishi Masataka, who served at the Second Demobilization Bureau—and records of the Y Committee, among other sources.