Japan Probe has a post titled "Pacifist group plans demonstration at Yasukuni". When I saw the Website of the "pacifist group", Anti-War Joint Action Committee, my blood froze. All of the member organizations of the committee were Chukaku-ha's organizations.
Chukaku-ha is a faction of left-wing extremists that is still holding the policy of armed revolution. It repeated bloody conflict with another left-wing faction Kakumaru-ha in the 1970s. Then, in the 1980s and 1990s, they repeated terror attacks to various places with explosives and firebombs. You can read a short summary on Chukaku-ha here on Wikipedia.
In the late 1970s, one of my acquaintances was seriously injured by this group. Late at night, when he was sleeping in his apartment room, a group of masked men broke into his room. They hit his right thigh with a hammer to break his thighbone and stabbed his left arm with an ice pick. Next morning, Chukaku-ha scattered bills stating that they annihilated a Kakumaru-ha member. The name of my acquaintance was written on the bill as the annihilated one. However, he had nothing to do with any left-wing groups. It seemed that they attacked him believing some misinformation. Suspects of that incident have not been arrested.
I found by google search that the following pages have a chronicle of incidents that Japanese left-wing radicals were involved in.
http://www.bordersphere.com/chrono/c.php4?s=1970
http://www.bordersphere.com/chrono/c.php4?s=1980
http://www.bordersphere.com/chrono/c.php4?s=1990
From the chronicle, incidents relating to Chukaku-ha are picked up below. Although only several incidents of the infighting between Chukaku-ha and Kakumaru-ha are shown in the list, to my knowledge far more number of bloody incidents took place in the infighting in the 1970s. The list is apparently incomplete.
Aug.4, 1970The chronicle ends here in 1990. For the incidents that took place after 1990, several news articles are available online.
Toshio Ebihara, a student of Tokyo Educational University [Tokyo Kyoiku Daigaku] and also a member of Kaku-maru-ha, was lynched to death by the members of Chukaku-ha in Hosei University. It was the first victim of the intra-sects violence [uchi-geba].
Nov.9, 1972
Kaku-maru-ha killed a student of Waseda University, Daizaburo Kawaguchi, by lynching, claiming him to be a member of Chukaku-ha, and left his body in front of Tokyo University Hospital. This opened a long bloody strife between the two sects.
Mar.14, 1975
Kaku-maru-ha killed the leader of Chukaku-ha, Nobuaki Honda, in his apartment in Kawaguchi City in Saitama Prefecture.
May.20, 1978
On the day of the inauguration of the Narita International Airport, Chukaku-ha cut the communication cables used for the Tokyo area flight control, in several locations in Tokorozawa City, Saitama Prefecture. This disorganized the flight schedule.
Feb.27, 1983
The Anti-Narita Air Port Alliance disintegrated into two factions, Kitahara-ha and Atsuta-ha; this dismembered the supporting sects: Chukaku-ha went with the former and The Fourth International went with the latter.
Sep.19, 1984
Chukaku-ha attacked the headquarter of the Liberal Democratic Party with a kind of flame thrower; seven floors, between the third to the ninth, were burnt.
Nov.27, 1984
Chukaku-ha set fire to the homes (and/or offices) of the governor Koichi Hamada and three Congressmen of Chiba Prefecture. (This was related to the Narita Airport affair.)
1985
Beginning from this year, New left Sects began to use the “projectile weapons” for the struggle against the Narita Airport expansion: arrow shaped bomb (Chukaku-ha), shell bomb (Kaiho, Hazama-ha) , M53 trench mortar (Bund, Senki-ha), etc.
Apr.12, 1985
Chukaku-ha attacked both Narita and Heneda Airports with eleven arrow shaped bombs, from a truck parked one kilometer away, with a time firing device.
Feb.8, 1986
With a time ignite device, Chukaku-ha set fire to several workings of Kajima Construction Company in Chiba City and Yamato City, that were used for the construction of Narita Airport.
May.4, 1986
Chukaku-ha shot five arrow shaped bombs to Geihin-kan [The National Guest House] where the Summit was taking place, from a building in Shinjuku Ward, located five kilometers away; one fell in front of the Canadian embassy.
Sep.1, 1986
Chukaku-ha attacked and killed the secretary general of the Japan National Railroad Workers Union in Osaka area, in his home in Itami City, Hyogo Prefecture. (It was part of the war between Chukaku-ha and Kaku-maru-ha.)
Nov., 1986
In a hideout of Chukaku-ha in Iwate Prefecture, the police discovered a powerful bomb, made from pressure cooker, being developed.
Mar.3, 1988
Chukaku-ha attacked and killed the secretary general of the East Japan Passenger Railway Workers Union of Takasaki area in his home. (It was part of Chukaku-ha vs. Kaku-maru-ha war.)
Jul.4, 1988
Chukaku-ha set fire to seven companies that were engaged in the second term construction of Narita Airport, by time ignition device; twenty nine trailers and trucks were burnt.
Sep.29, 1988
Chukaku-ha set fire to two cars parked in the dormitory of the Supreme Court in Shibuya Ward in Tokyo, by time ignite device.
Oct.25, 1988
Employing time ignite devices, Chukaku-ha set fire to three vehicles in a construction site of the Japan Road Public Corporation [Nihon Doro Kodan], in Koyama-cho in Shizuoka Prefecture.
Nov.3, 1988
Chukaku-ha set fire to two big trucks of a transportation company in Taiyo-mura in Ibaragi Prefecture.
Jan.29, 1989
With a time-bomb, Chukaku-ha exploded the storage of a home of the chair man of the committee for deciding uses of public land (of the Ministry of Construction); it destroyed parts of the home and other seven homes near by.
Feb.28, 1989
Chukaku-ha attacked and killed the secretary general of the eastern section of JR Union (of Kakumaru-ha).
Mar.7, 1989
In Tsukuba City Ibaraki Prefecture, Chukaku-ha‘s time ignite device burnt two storage buildings of Nihon Hoso, the company that was in charge of building roads for Narita Airport.
Mar.12, 1989
With time ignite device, Chukaku-ha burnt three large trucks in a parking lot for a construction company in Tomizu City, Chiba Prefecture.
Mar.20, 1989
With time ignite device, Chukaku-ha burnt a large truck, an excavator, and a resting room for the workers in the site of constructing an overflow in Narita City in Chiba Prefecture.
Apr.29, 1989
Chukaku-ha set a time bomb in a private car in a parking lot of the Imperial Household Agency in Chiyoda Ward in Tokyo; it destroyed the car and a bike as well as the window glasses of the dormitory.
June 5, 1989
With time ignite devices, Chukaku-ha burnt seven large trucks in a parking lot of a transportation company in Numanan-cho in Chiba Prefecture.
Jul.24, 1989
With a time ignite device, Chukaku-ha burnt parts of the home of the secretary general of the committee of land expropriation of Chiba Prefecture.
Aug.23, 1989
With a time ignite device, Chukaku-ha burnt parts of the resting room for the workers in a golf club in Shibayama-cho in Chiba Prefecture.
Sep.8, 1989
With a time ignite device, Chukaku-ha burnt the office, storage, and five vehicles of a construction company in Narita City in Chiba Prefecture.
Nov.16, 1989
With a time ignite device, Chukaku-ha burnt the house of the secretary general of the Chiba Prefectural Parliament; parts of two neighboring houses, too, were burnt.
Dec.7, 1989
With a time ignite device, Chukaku-ha burnt a half of the home of an official of Chiba Prefecture’s Planning Department, in Chiba City.
Jan.8, 1990
Aiming at the residence of Prince Tokiwa, Chukaku-ha shot shell bombs from a time set launcher installed in a car parked in a construction site in Shibuya Ward in Tokyo; they fell in the parking lot of Japan Coca Cola headquarter and the residence hall of the Imperial Household Agency across the street from the target. About the same time, similar shell bombs were shot from a shrine near Kyoto Imperial Palace; they fell near the palace.
Jan.16, 1990
With a time ignite device, Chukaku-ha burnt the office and three other buildings of Mitsui Construction that was involved in the construction of Narita Airport, in Atsugi City in Kanagawa Prefecture.
Jan.23, 1990
With a time ignite device, Chukaku-ha burnt the passenger seats of the six lines of JR and a line of Keisei line around Tokyo area.
Feb.19, 1990
With a time ignite device, Chukaku-ha burnt part of the home and the car of the director of information administration of the Ministry of Transportation in Yachiyo City in Chiba Prefecture.
Feb.27, 1990
With a time ignite device, Chukaku-ha burnt part of the home of the president of Shimizu Construction that was involved in the construction of Narita Airport, in Setagaya Ward in Tokyo.
Mar.7, 1990
With a time ignite device, Chukaku-ha burnt part of the home of the managing director of the New Kansai Airport Corporation, in Habikino City in Osaka.
Mar.14, 1990
With a time ignite device, Chukaku-ha burnt cars parked in an underground parking lot of a building in Akasaka Ward in Tokyo; the cars belonged to the Nuclear Energy Development Corporation. A fireman of the Tokyo Fire Defense Agency was killed during the rescue mission.
Mar.19, 1990
Allowed by the New Narita Legislation [Narita Shin-po], the government (the Ministry of Transport and the Airport Public Corporation) forcibly removed the base of Chukaku-ha located in the site of Narita Airport expansion.
Mar.19, 1990
With a time ignite device, Chukaku-ha burnt three shrines (Hikawa Shrine in Numabukuro, Nakano Ward, Shinmei Shrine in Funabashi, Setagaya ward, and Shirahige Shrine in Higashi Muko-jima in Sumida Ward) in Tokyo area
Mar.22, 1990
With a time ignite device, Chukaku-ha burnt a garage of the residence of Japan Airline’s President at large (kai-cho), and a garage of the residence of All Nippon Air’s president.
Apr.12, 1990
With a time ignite device, Chukaku-ha burnt the entire home of the managing director of the Nihon Hikoki in Kamakura in Kanagawa Prefecture; his wife was killed and the director was heavily injured.
Tokyo Police Posts Bombed as Emperor Rite Nears. (Nov. 3, 1990; New York Times)
Chukaku-ha leftists admit torching buses in Chiba. (June 4, 1998; Japan Times)
Guerrillas blamed for morning attack: Transport Ministry official's car, house damaged but no injuries reported. (Aug. 27, 2000; Japan Times)
Chukakuha radicals claim responsibility for explosion. (Jan. 25, 2001; Kyodo)