Onna gokoro (1959)

Married for almost a decade, a couple with a son called Kenichi have their life thrown for a loop when the wife Isoko (Hara Setsuko) comes across a photo of her university professor husband Asakichi (Masayuki Mori) with a younger woman called Teure (Reiko Dan), alongside a gift and a letter. When the husband is confronted he admits to merely loving his wife non-romantically prompting her to take her son and leaving the house. While she returns to her previous job and staying at the company's dormitory, her husband is being visited by the other woman, who wants to tend to him, and the professor's students.