Shiawase no Yokan (1996)

Shiawase no Yokan 1996 / 幸福の予感 1996 / The Premonition of Happiness

Akiko and Kenichiro get married, but Akiko is hit hard by her mother-in-law, Kiyono, because she has a good relationship with her husband but cannot have children. Shortly after her marriage, Kenichiro begins to feel signs of affair. Her partner is Kumiko, Kenichiro's sub-ordinate. Due to her twists and turns, Kumiko becomes Kenichiro's wife, but she again shows signs of cheating on Kenichiro. How, the cheating partner was a man. (Source: Japanese Wikipedia)