Odd Obsession
鍵 (original)
Starring Machiko Kyō, Junko Kano, Tatsuya Nakadai, Saburo Date, Jun Hamamura, Ganjirô Nakamura II, Tatsuo Hanabu, Tanie Kitabayashi, Kôshi Kosugi, Mayumi Kurata
It's a drama movie, and has a rating of 6.9 out of 10 from Imdb which is usually fine for this kind of movie.
Watch it here
Not found streaming from Italy.