The fake far right movement in Japan run by Koreans pretending to be Japanese. Probably at least partially funded by the Korean government (north or south). Affiliated with the yakuza (also controlled by Korean "zainichi").
Like neoconservative Jews in America, the uyoku dantai Koreans' goal is to undermine the traditional right wing in Japan and make it look a stupid caricature to mainstream Japanese, while at the same time making it serve their own purposes (weakening Japan with immigration, crime, etc.).
uyoku dantai yelling in the street: "My name is Kim Chon I mean Satoshi Nakamoto! Long live the Emperor! Tenno Banzai! Annyeonghaseyo!"