The film is a warning to young people who are addicted to tobacco, which not only leads to infertility as in the medicine envelope but can also lead to cuckolding =)).
Manami Oura's husband is a terrible smoker, he goes to the door every day 10 times, 5 minutes each time, and that's the time when the lewd father-in-law cuckolded his son. Taking advantage of only those 5 minutes, he played with his daughter-in-law, shot and butterfly his daughter-in-law, and so on regularly 10 shots a day, which was very powerful :))