Kuroda’s insistence on going it alone. Chūkaku-ha era Starting in the mid-1960s, Chūkaku-ha, became active in organizing protest activities. In 1966, Chūkaku-ha joined in alliance with two other radical student groups, the "Second Bund" (Daini Bunto) and the Liberation Faction of the Socialist Youth League (Kaihō-ha) to form the "Three-Faction" (Sanpa) Zengakuren. As part of the Sanpa Zengakuren, Chūkaku-ha participated in the October 8, 1967 protest at Haneda Airport which attempted to block Japanese Prime Minister Eisaku Satō from visiting South Vietnam. In 1968, they protested the visit of the nuclear-powered aircraft carrier, , to Sasebo. Later that same year Chūkaku-ha participated in another protest of the Shinjuku Rail Station's transportation of US forces fuel tanks, remembered as the "Shinjuku Riot." Beginning in 1968, Chūkaku-ha became involved in the Sanrizuka Struggle assisting farmers in violently opposing the construction of Narita Airport outside of Tokyo. Some members of Chūkaku-ha remained deeply involved in this struggle well into the 1980s. In 1968 and 1969, the organization promoted several protests at campuses across Japan. Throughout this period and into the 1970s, Chūkaku-ha was engaged in violent conflict with their archrivals in Kakumaru-ha. During the conflict, Kakumaru-ha assassinated several members of Chūkaku-ha, including its leader Nobuyoshi Honda in 1975. According to Chūkaku-ha, Kakumaru-ha was aided and protected by the police. Starting in the late 1970s, the group began committing armed assaults, bombings, and destruction of infrastructure in Japan. There were a fair number of casualties and injuries as a result of the dozens of attacks they conducted. Casualties included the chairperson of Chiba prefecture's Expropriation Committee, whose death delayed the area's development. In 1986, their covert weapons factory was raided by police after two suspects were arrested for carrying an explosive in their truck. Chūkaku-ha's attacks continued into the later part of the 20th century, with the last one occurring in 2001. Today, Chūkaku-ha still stages protests and is known to use a YouTube channel to draw attention to their activities. In 2017, the MPD announced the arrest of Masaaki Osaka, a known Chūkaku-ha leader accused of killing a police officer during a riot on November 14, 1971. On that day, a protest against the occupation of Okinawa by the United States turned violent, with students throwing Molotov cocktails at officers. Takeo Shimizu, one of Chukaku-ha's surviving leaders, appeared in public after going underground since 1971 on September 6, 2020 at Arakawa, Tokyo. During