It's been 20 years since mass murderers came to Toshie Koibuchi's tiny street. It was the night of June 27, 1994. She was then 50, a housewife living with her husband and mother in a slightly upmarket residential area of Matsumoto, Nagano Prefecture.

Koibuchi had a late dinner and took a bath around 10 p.m. She enjoys a long bath. It is not clear whether that's what saved her or nearly killed her — more likely the latter.

While she was bathing, a group of men from the religious group Aum Shinrikyo sat in two vehicles parked about 30 meters from her house. One of the vehicles was a minivan, the other a truck that had been converted into a toxic mobile gas chamber.