Japanese Prime Minister Shinzo Abe is expected to sign a deal with his Australian counterpart in Tokyo next week to jointly develop and market military equipment.
Tokyo has moved swiftly to take advantage of recent legal changes covering the development and export of defence equipment that went into effect on Tuesday and give more leeway to Japanese firms' exports.
Defence sector companies in Japan have long been calling for a rethink of the government's position and hope to be able to sell their cutting-edge military technology to other countries.
Tokyo's decision has drawn criticism from China and South Korea, with Seoul demanding that Tokyo ensures "transparency" in any deals and Beijing insisting that Japan "does more" to ensure peace and stability in the region.
Japan has been reaching out to regional powers to counter what it sees as the growing belligerence of China, particularly in territorial disputes, and the deal with Canberra is designed to help cement the bilateral defence relationship.
Tony Abbott, the Australian prime minister, will next week become the first foreign leader to attend a session of Japan's National Security Council, which was set up in December.
Defence officials in Tokyo declined to comment on the reports by Kyodo News and the Yomiuri newspaper, but there is also expected to be closer co-operation is information and intelligence exchanges.
Before the new export rules, Japan also started discussions with France on the creation of a panel to share data on equipment - such as helicopters - with both civilian and military uses.
The Japan Technical and Research Institute, which comes under the Ministry of Defence, and its British counterpart, the Defence Science and Technology Laboratories at Porton Down, Wiltshire, have also started to collaborate on the development of clothing to protect against chemical, biological, radiological and nuclear threats.
Other early joint projects will focus on the development of equipment for humanitarian crises, peace-keeping operations and disaster recovery efforts.