The Watcher in the Attic (1976)

Based on a story by well-praised Japanese writer Edogawa Rampo. In Tokyo, 1923, Saburo Gouda is exploring secrets of his fellow-occupants of an apartment building. All from above, using spy-holes bored in ceilings of his neighbors rooms. After he sees a meeting between aristocratic (and bored) Lady Minako and a clown, he realizes, that pursuit of Minako's blooming dark realm of senses is drawing themselves by the corruption they both experience and cause.