Movie about an old woman telling her life story to a film crew
You are referring to the 2001 film "Millennium Actress" (Sennen Joyû) by director Satoshi Kon.


  A movie studio is being torn down. TV interviewer Genya Tachibana has tracked down its most famous star, Chiyoko Fujiwara, who has been a recluse since she left acting some 30 years ago. Tachibana delivers a key to her, and it causes her to reflect on her career; as she's telling the story, Tachibana and his long-suffering cameraman are drawn in.