After decades of decline, the sudden emergence from about 2006 of a new style of hard-right organization has greatly changed the landscape of rightist politics in Japan. In Japan, this is referred to as the Action Conservative Movement (ACM), or Kōdō Hoshu Undō. ACM groups have a strong nativist streak, and are known for their use of hate speech against foreigners in general and Koreans in particular. This paper, the first in a collection of four, sketches in the historical, social and political background against which the ACM has arisen. It covers the development of Japan’s ethnic minorities, with particular reference to the Zainichi Koreans, Japan’s largest and longest-standing ethnic minority, whose so-called ‘special privileges’ are a particular target of the ACM. It shows how a gradual liberalization of the treatment of foreigners in Japan has gone hand-in-hand with a strengthening emphasis on patriotism under successive administrations. This apparent paradox of governance, along with the spread of internet chatrooms and live streaming of political demonstrations, are the main factors identified in the rise of the ACM.