What Is It?
The 1997 Japanese anime (animated) psychological thriller mystery movie Perfect Blue.
Here is how Wikipedia describes this anime movie:
Perfect Blue (Japanese: パーフェクトブルー, Hepburn: Pāfekuto Burū) is a 1997 Japanese animated psychological thriller film directed by Satoshi Kon. It is based on the novel Perfect Blue: Complete Metamorphosis (パーフェクトブルー：完全変態, Pāfekuto Burū: Kanzen Hentai) by Yoshikazu Takeuchi, with a screenplay written by Sadayuki Murai. Featuring the voices of Junko Iwao, Rica Matsumoto, Shiho Niiyama, Masaaki Okura, Shinpachi Tsuji and Emiko Furukawa, the plot follows a member of a Japanese idol group who retires from music to pursue an acting career. As she becomes a victim of stalking, gruesome murders begin to occur, and she starts to lose her grip on reality.
Like much of Kon’s later works, such as Paprika, the film deals with Kon’s longstanding theme of the blurring of the line between fantasy and reality.