On November 5, 1989, Tsutsumi Sakamoto (坂本 堤 Sakamoto Tsutsumi April 6, 1956 – November 5, 1989), a lawyer working on a class action lawsuit against Aum Shinrikyo, a doomsday cult in Japan, was murdered, along with his wife Satoko and his child Tatsuhiko, by perpetrators who broke into his apartment.

Furthermore, religious items were being sold at prices far greater than their market value, draining money out of the households of members (in a practice called spiritual sales).

[citation needed] After Sakamoto's disappearance, lawyer Taro Takimoto took over most of his anti-Aum Shinrikyo legal activities.

However, the network secretly showed a video of the interview to Aum members without Sakamoto's knowledge, intentionally breaking its protection of sources.

[5][6] Several days later, on November 3, 1989, several Aum Shinrikyo members, including Hideo Murai, chief scientist, Satoro Hashimoto, a martial arts master, Tomomasa Nakagawa and Kazuaki Okazaki drove to Yokohama, where Sakamoto lived.

According to court testimony provided by the perpetrators later, they planned to use the chemical substance to kidnap Sakamoto from Yokohama's Shinkansen train station, but, contrary to expectations, he did not show up—it was a holiday (Bunka no hi, or "Culture Day"), so he slept in with his family at home.

[citation needed] The family's remains were placed in metal drums and hidden in three separate rural areas in three different prefectures (Tsutsumi in Niigata, Satoko in Toyama, and Tatsuhiko in Nagano) so that in case the bodies were uncovered, police might not link the three incidents.

[10] As reported by NHK in 2015, the Tokyo metropolitan police had received a tip that an Aum member was involved in the murder, and in 1991 launched an investigation into the cult's facilities in the city.

[13][14] After the culpability of Tokyo Broadcasting System in the murders was uncovered, the network was swamped with complaints and eventually the company's president resigned.

[15] Following the Tokyo attacks, police charged Aum members Hideo Murai, Tomomasa Nakagawa, Kazuaki Okazaki, and Satoro Hashimoto with the murder of the Sakamoto family.