Japan Socialist Youth League, Liberation Faction

The Japan Socialist Youth League, Liberation Faction (日本社会主義青年同盟解放派, Nihon Shakaishugi Seinen Dōmei Kaihō Ha), usually abbreviated Kaihō-ha ("Liberation Faction"), was a Japanese radical Marxist group active in the 1960s and 1970s as part of the Japanese New Left. Kaihō-ha had a young workers wing and a student wing. Their student wing was called the "Anti-Imperialist Student Council" (反帝学生評議会, Hantei Gakusei Hyōgikai). They wore blue helmets when engaging with hand-to-hand combat with other radical groups or the police.

Kaihō-ha played a major role in several of the protest movements of the era, including the 1968-69 Japanese university protests and the Sanrizuka Struggle against the construction of Narita Airport.