gakusei_undou
A Japanese term for student activism that is often used to refer to the Japanese New Left wave from the 1950s to 70s, its political movements and groups.
Various individual groups, political movements and incidents are associated with this term. For example the Kakumaru-ha, the Chuukaku-ha, the post-50s Zengakuren, Zenkyoutou, Toudai Funsou, etc. When one of those organizations, the Rengou Sekigun, caused the Asama-Sansou incident, and members of the Nihon Sekigun were found to be involved in the Lod Airport massacre, they lost all support from the public and went into decline, even impacting broader political discussion by rendering it a private matter.
They are stereotyped as being equipped with construction helmets, dust masks and square timber (sometimes steel pipes and Molotov cocktails), sticking flyers with various propaganda slogans (for example, "Never allow!!" "Crush the unfair **!!" "We will win this conflict!!" etc.) all over the place, and for separating into numerous groups and infighting. The various portmanteaus using Geba and Aji were created from student activism, and each derive from "gewalt" (German for "violence") and "agitation".
The square timber mentioned earlier are called geba-bou (gewalt stick), internal conflict is called uchi-geba (internal gewalt), flyers are aji-bira (agitation flyers), and the fonts used for these purposes are called geba-moji (gewalt fonts).