Yasuo Hayashi, Kazuaki Okazaki, Masato Yokoyama, Satoru Hashimoto, Toru Toyoda and Kenichi Hirose — who had been on Death Row for 20 years — were hanged on Thursday, July 26.
It follows the execution of the cult's leader Shoko Asahara earlier this month.
Aum Shinrikyo gained official status as a religious organization in Japan in 1989 and gained a sizeable following around the world.
But during the morning rush hour on March 20, 1995 cult members released capsules of deadly sarin nerve gas on the Tokyo subway, killing 12 people.
Three 'Spin-Off' Cults
Asahara and other cult members were captured, convicted and spent 20 years on Death Row.
Sarah Hightower, an independent researcher, said Aum Shinrikyo had three "spin-offs" — Aleph, Hikari no Wa and Yamada-ra no Shuudan.
"Aum Shinrikyo was a syncretistic blend of yoga, esoteric Buddhism, Hinduism, New Testament Christianity, and various forms of new age mysticism. They also incorporated anti-Semitic propaganda influenced by Protocols of the Elders of Zion into their belief system. Asahara was inspired by the Book of Revelations and the Nostradamus boom to begin preaching his doomsday rhetoric. Members absolutely believed that 'harumageddon' was a certainty. Towards the end, many didn't even expect to survive. He prepared them for 'a death without regret'," Ms. Hightower told Sputnik.
The successor cults remain legal in Japan although the Japanese have designated them "dangerous religions" and cult members are kept under surveillance by the National Police Agency and the Public Security Intelligence Agency (PSIA).
'Aleph Is Aum By Another Name'
"Aleph is Aum with a new name. It is the exact same cult it was in 1995….the cult was renamed Aleph as an attempt to subvert potential legal measures," Ms. Hightower told Sputnik.
She said Aum's popular spokesman, Joyu Fumihiro, was expected to take over as leader of Aleph but he left to create Hikari no Wa in 2007 because he wanted to distance the cult from Asahara.
"Yamada-ra no Shuudan is a group of about 30 Asahara loyalists who split from Aleph and set up a separate base in Kanazawa," Ms. Hightower told Sputnik.
"All three groups are under constant surveillance and random inspection by the authorities….Aleph is considered to be a threat. Yamada is thought to be just as dangerous as Aleph. Hikari no Wa, according to my sources, is not considered a terror threat. But Joyu is a very controversial figure and the authorities are keen to keep an eye on him. All three groups were raided on the day Asahara was executed," Ms. Hightower told Sputnik.
Battle For Asahara's Ashes
Asahara's execution set off a battle among his relatives with his wife and several children who are in various successor cults seeking to obtain his ashes.
But his youngest daughter, who has completely broken with the cults and has never been named in order to protect her, said she wanted to scatter his ashes at sea to avoid creating a pilgrimage site.
Death threats have been made to Taro Takimoto, a lawyer representing the daughter.
"Mr. Takimoto and Asahara's fourth daughter are currently petitioning the Japanese government to give Asahara the Bin Laden treatment. Mr. Takimoto is a survivor of multiple assassination attempts by Aum… Aleph will do whatever they can to retrieve Asahara's remains. They still worship him as an absolute god. For that reason, wherever his ashes are scattered will become sacred ground to the remaining worshippers," Ms. Hightower told Sputnik.
Hundreds of commuters were hospitalized in the attack, which was carried out with sarin produced at the cult's headquarters in the foothills of Mount Fuji.
Aum Produced Enough Sarin To Kill Millions
Aum Shinrikyo had actually produced enough sarin — a gas first used in the First World War — to kill millions.
The cult members had also carried out a sarin gas attack in Matsumoto in 1994 and also murdered an anti-cult lawyer and his family.
Many cult members remain in prison for other crimes.
The Japanese government decided to carry out the executions this year before the abdication of Emperor Akihito, who has been on the chrysanthemum throne since 1989.
The 1995 attack was the low point of the Heisei imperial era, and came during the so-called "lost decade", when Japan's economy stagnated and more and more young people became restless and discontent.
'Poor Taste' To Have Executions During Change Of Imperial Era
"Traditionally some prisoners are granted amnesty when the imperial era changes. They wanted to avoid any and all speculation regarding the 13 Aum prisoners following the end of the trials in January. Culturally it is considered in poor taste to speak of or report on things like murder or mass executions during an event such as the coronation of a new emperor. They didn't want negative press to cloud the succession proceedings," Ms. Hightower told Sputnik.
"With the 13 members executed, perhaps the case is closed from the point of view of criminal justice. But the damage done to the victims continues even after the executions. I find it very hard," said Shizue Takahashi, whose husband was killed in the subway attack.
"The taking of a life in retribution is never the answer," Amnesty International's East Asia researcher Hiroka Shoji said in a statement on Thursday, July 26.
"I ordered the executions after extremely careful consideration," Justice Minister Yoko Kamikawa said at a press conference.