The Tokyo city government said Thursday members of the public had pledged almost one billion yen ($12.5 million) to its drive to buy a group of uninhabited islands at the centre of a row with China.
About 864 million yen has already been sent to a bank account Tokyo's metropolitan authorities opened less than a month ago to accept citizen donations, according to the city's latest tally.
Separately, Tokyo Governor Shintaro Ishihara said he has had an offer of 100 million yen from an entrepreneur, although the money has not yet reached the city's coffers.
Ishihara re-ignited a long-simmering maritime territorial dispute in April when he vowed to buy a group of islands in the East China Sea, called Senkaku in Japan and Diaoyu in China.
The uninhabited islands sit around 2,000 kilometres (1,250 miles) from Tokyo in rich fishing grounds that may harbour lucrative energy resources.
Ishihara, an outspoken critic of Beijing who has made a career out of provocative nationalistic remarks, said he had approached the islands' private owner with view to buying the titles to three of the five.
They are presently owned by a Japanese family and leased to the Japanese government for a total annual rent of 24 million yen.
China and Japan are bickering over the island chain and a recent Uighur symposium in Tokyo that angered Beijing, which said Wednesday it had cancelled a high-level military trip to its neighbour.
Guo Boxiong, vice chairman of the powerful Central Military Commission and China's highest ranking military officer, would not visit Japan due to "work commitments" at home, the defence ministry said in a statement.