Masami Tsuchiya

was a Japanese convicted terrorist and senior member of Aum Shinrikyo, responsible for the deaths of a combined 19 people and for the production of sarin, VX nerve agent, PCP, and LSD. He served in Aum's "Ministry of Health". Prosecutors described him as "the second most important figure involved in the gas attacks by the Aum Shinrikyo cult" after Aum leader Shoko Asahara himself.

Biography Masami was a native of Chiyoda, Tokyo. His early childhood was filled with sensations of deja vu that he did not understand and would never get a satisfactory answer when he would ask about them. He also wanted to make sense of religious feelings. He planned to go to the Himalayas, but he then felt this was unrealistic, so he went to college. In the summer of 1986, his girlfriend ended their relationship. He then cut himself with a knife from his shoulder and his hip. He tried to make sense of this experience.

Tsuchiya's first encounter with Aum Shinrikyo was when a friend took him to a Japanese meditation hall. Tsuchiya joined Aum Shinrikyo in the summer of 1991 after running away from his parents who had confined him to their home after he started skipping college in June 1990. He took refuge at an Aum dojo and became a monk on September 5th, 1991. Tsuchiya had a master's degree in physical chemistry and organic chemistry.

Tsuchiya was notably loyal to Asahara, describing himself as a "direct disciple of the guru", and referring to Asahara as . and the Supreme Court affirmed the ruling in February 2011, concluding that Tsuchiya had played a decisive role in the 1995 subway attack. In response, Tsuchiya said, "Natural result. I wanted to think about what I could do with a lifelong apology."

On 6 July 2018, Tsuchiya was executed along with Asahara and five other cult members.