Kanda couple celebrates 40 years of marriage. Ruriko has been a homemaker while her husband, Hiroaki, worked at the prefectural office, both leading busy lives dedicated to raising their sons. Their eldest daughter has now married and their long-awaited first grandchild is born. Filled with joy, Hiroaki retires from work to care for the baby with his wife. Cherishing their newfound free time, they go on a hot spring trip together as a family. Sharing warmth in the family bath, they reaffirm the deep bond they've nurtured over four decades.