The brief modern history of the "disputed" Northern Territories.

中國企業考察北方四島，日本為何滿地打滾？ _風聞 

PS. On my business trip to Tokyo half a century ago, I saw a rightist rally on the street chanting "Return us the Northern Territories". FYI, one of the other slogans of the rally was "Firmly support Chiang Regime in Taiwan." Ha!