This film is bookended alluding to a civilian gas attack: six years before it was made, the "doomsday cult" Aum Shinrikyo (with at height, 10,000 followers - including many university educated graduates) sarin gas attacked the Tokyo subway (13 dead) in March '95: after conviction its leader, Shoko Asahara (real name Chizuo Matsumoto), with "six other seniors", were finally state executed by hanging in Japan, 23 years later in July 2018. Six others remain condemned. [Japanese Justice Ministry 6.7.18.]