to a pair of islets controlled by Seoul.
"The boycott is to show the resolve of merchants to protect Dokdo," Oh Ho Seok, head of the Save Local Stores Alliance, was quoted as saying by Yonhap News Agency.
'Dokdo' is the Korean name for the islets, which are known as 'Takeshima' in Japanese.
Organizations such as the Federation of Professional Economic-Person Societies, Voter Citizenship Behavior and Save Local Stores Alliance, which have a combined 6 million members, said they will opt not to buy or sell Japanese products starting Friday.
The move by the merchants is the first nationwide effort to boycott products and is timed to start on March 1, a national holiday in South Korea to commemorate a popular uprising to resist Japanese colonial rule in 1919.
In the past, smaller organizations have taken such steps with limited impact.
The products that will be affected the most are Mild Seven cigarettes and Asahi beer, although campaigns not to buy Nikon cameras and Uniqlo clothes along with products made by Sony, Toyota and Honda will be pursued as well, Yonhap said.
The boycott is to be in protest against Japan's holding of an event last Friday to promote its claim to the islets, despite Seoul's calls for restraint.
A senior Japanese government official also attended the event at Shimane Prefecture.
The boycott, meanwhile, is expected to have an impact because the merchants and the stores they own such as small supermarkets and restaurants handle roughly 80 percent of all Japanese products in the country.