It's been two years since I got married, and my in-laws are worried about not being able to have children, and they plan a two-day, one-night, baby-making hot spring trip. "Have you been abstinent as promised? Please do your best during this trip and show us your healthy grandson quickly." My father-in-law's wish is futile, and indeed, my wife becomes unwell and falls asleep. After a month of abstinence, I spend a sleepless night in agony, but while wandering around the inn late at night, I happened to see my stepmother taking a bath...