Although less widespread than before, a "significant" number of xenophobic rallies organized by nationalist groups still occur on a regular basis in Japan, the Justice Ministry revealed Wednesday in its first-ever probe into hate speech.

The investigation into hate speech, which began to manifest itself around 2013 amid Japan's deteriorating relations with South Korea, found that anti-Korean activist group Zaitokukai and other ultraconservative organizations held 1,152 rallies on various themes from April 2012 to September 2015.

A total of 347 happened in 2013, 378 in 2014 and 190 from January through September in 2015.