Sakhalin Info reported on Friday that the fighters were sent to Yasniy Airport on Etorofu Island.
Russia's Defense Ministry has yet to formally comment, but the report says this is the first step toward full-scale deployment.
A photo obtained by NHK shows at least 3 parked Su-35s.
Yasniy Airport was opened 4 years ago as a civilian airfield. But the Russian government decided in January this year to allow both military and civilian aircraft to use the facility.
In March, Russian fighters landed there during a training exercise.
The deployment of fighter jets to the airport is seen as part of an attempt by Russia to increase its military capability on the 4 islands.
Russia considers those islands and another nearby island chain to be military strategic points facing the Pacific Ocean.
Russia controls the 4 islands. Japan claims them. The Japanese government maintains the islands are an inherent part of Japan's territory. It says the islands were illegally occupied after World War Two.
Major Japanese restaurant chain Gusto on Monday stopped providing plastic straws at its 1,300 locations nationwide.
(NHK) 
Tokyo prosecutors have indicted former Nissan Motor chairman Carlos Ghosn for understating his past compensation by tens of millions of dollars. They have also served an additional arrest warrant on him over similar allegations relating to his pay in the last 3 years.
(NHK) 
Winter bonuses at Japanese companies averaged an all-time high of 834,391 yen ($7,400) this year, according to a Nikkei survey released Monday, notching a sixth straight year of growth on strong corporate earnings. (Nikkei) 
Saitama Prefectural Police have arrested a 39-year-old man over the stabbing of three Cambodian nationals at an apartment building in Hanyu City on Saturday, reports NHK (tokyoreporter.com) 
Crown Princess Masako, who turned 55 on Sunday, vowed to make her best effort to serve the people as she is set to become Empress following May’s Imperial succession. (Japan Times) 
Japan is set to extend the copyright period on works such as novels and paintings to 70 years after the authors’ deaths from the current 50 years, effective Dec. 30, when the revised copyright law goes into force. (Japan Times) 
A Chinese court has sentenced a Japanese woman to six years in prison for spying, a source privy to bilateral relations said Saturday. (Japan Today) 
The Diet on Saturday approved an economic partnership agreement with the European Union that’s set to create a free trade bloc accounting for 30 percent of world output.
(Japan Times) 
Gunma Prefectural Police have arrested a staff member for the National Police Agency over the alleged rape of a 12-year-old girl he met online earlier this year, reports the Sankei Shimbun (tokyoreporter.com) 
Japan's ruling coalition has pushed a controversial bill through the Diet with just a few days left before the current session ends. It will allow more foreign workers into the country.
(NHK)