Gunsmoke (1966)

O Jin-u of a rich family and a female private tutor at his house are in love, but his family are against their marriage and send him to America. Before he leaves for America, they hold their own wedding and vow to love forever. But once out of sight, her devotion weakens with time and falls in love with Jin-u's friend Seong-hun. Hearing about the fact, Jin-u hurriedly returns to fight a duel with him...