Cure

• The film was originally titled 'Evangelist' (Dendoushi), but Kurosawa and Daiei changed it during production after the Aum Shinrikyo cult's 1995 Tokyo subway sarin attack made any cult-leader/preacher framing toxic in Japan (Wikipedia, Far Out Magazine).
• It's the first collaboration between Kiyoshi Kurosawa and Koji Yakusho, who plays detective Takabe—a pairing that went on to span Charisma, Pulse-era work, and decades of Japanese cinema (multiple sources via search).
• Cinematographer Tokusho Kikumura shot the murders in cold, deep-space wide shots that hold the killings at a distance instead of cutting in close, keeping the violence detached and dread-soaked rather than gory (search results).
• Bong Joon-ho watched Cure while making Memories of Murder and modeled aspects of his killer on Mamiya; he later placed Cure in his top ten in the 2012 Sight & Sound directors' poll and has called it one of the films that shaped his view of cinema (Screen Daily, Tilt Magazine, Wikipedia).
• Cure predates and helped trigger the late-'90s/2000s J-horror wave—arriving before Ringu, Ju-On/The Grudge, and Audition—and is widely credited as a progenitor of that whole export boom (Tilt Magazine, search results); it carries a 94% Rotten Tomatoes score.
• Mamiya's hypnotic method is built on real history: the script grounds his 'mesmerism' in Franz Mesmer's animal magnetism, and Takabe uncovers an old phonograph cylinder and footage tying the technique to a 19th-century Japanese hypnotist tradition (Wikipedia, search results).

Mamiya is a vacancy, not a villain. His amnesia isn't an act and his murders aren't the point—he's an empty vessel whose only function is to hollow out everyone he meets by asking 'Who are you?' until their sense of self collapses and whatever they've repressed walks out. Read this way the film argues that the 'cure' is erasure: the killers aren't possessed, they're finally relieved of the identity that was suppressing them.

Takabe doesn't stop the contagion—he inherits it. The diner ending, where a waitress quietly fetches a knife after a glance from her manager, plays as confirmation that Takabe has become the new transmitter. His wife Fumie's mental decline and her death with the same X mark frame him as already infected long before the finish; the hunter was always the next carrier, and the case had no cure because it was never meant to be solved.

Cure is really about late-'90s Japan as a society of pre-loaded killers, not one bad man. Every murderer is an ordinary person—a cop, a doctor, a wife—who needed only the lightest push to act on a violence already inside them. Anchored in the post-sarin-attack title change, the film reads as a portrait of a repressed, anxious culture where Mamiya is just the match, and the kindling was everyone.

Tokyo is drowning in murders that make no sense: ordinary people slaughter someone close, carve a deep X into the throat, then sit calmly waiting for the police with no memory of why. Every killer is different. Every killing is identical. Detective Takabe traces the rot back to Mamiya, a drifting amnesiac who answers every question with one of his own—"Who are you?"—until the person across from him forgets too. A lighter's flame, the slosh of water, and the wall inside someone quietly comes down. Kurosawa turns a serial-killer hunt into something colder: an idea that spreads, and a cop who keeps staring into it.