Shigeru Aoyama

After her husband's suicide, young and beautiful Mitsuko Fuji feels alone and helpless -- until one of her husband's major creditors, Mr. Kito, offers a sympathetic ear and a cancellation of all debts. However, Mitsuko soon learns that Kito's intentions are anything but pure, as she's forced to become his personal concubine. Her only, improbable hope for redemption lies with her one true admirer: Kito's very own son.

Pinku from 1966.

Professor Katayama tries to balance relationships with his mistress, plus another teacher's wife, and two different perky students, while attempting to keep his wife in the dark.