Groper Train: Feels Like Climax (1986)

Japan's first space shuttle crashes into the mountains, and it is reported that all crew members are killed, except for one woman, Ozora Mirai, whose body is never found. A few days later, while trying to molest her on the train, Matsutaro is approached by a dirty woman, who clings to him and he has no choice but to take her back to his apartment. This woman is Mirai, who has lost her memory due to the shock. Mirai's stepmother Reiko finds out that Mirai is still alive and is trying to kill her to monopolise her inheritance.