Jôi-uchi: Hairyô tsuma shimatsu

Isaburo Sasahara (Toshiro Mifune) is an aging swordsman living a quiet life. When his clan lord orders his son to marry the lord's mistress, who recently displeased the ruler, Isaburo reluctantly takes in the woman. His son and the mistress fall in love, much to the family's surprise, but the lord soon reverses his decision and demands the mistress's return. Against all expectations, Isaburo and his son refuse, risking the destruction of their entire family.