Shutter (2004)

Tun, a photographer, and his girlfriend Jane are driving home one night when they hit a young woman on the road. Tun insists that they drive away without helping. Soon after, Tun finds strange white shadows and faces in his photographs, and he suffers from heavy pain in his neck and shoulders.

Jane looks into spirit photography and becomes convinced the images are of a ghost. At the same time, Tun's college friends begin to die by suicide, one after another, each of them haunted before they die.

Jane discovers that the ghost is Natre, a shy young woman Tun dated in college but kept secret. When Natre became too attached, Tun's friends sexually assaulted her, while Tun took photographs and did nothing to stop them. Natre later took her own life. Tun had hidden all of this from Jane.

Jane and Tun travel to Natre's family home and find her body, still in her bedroom, kept by her mother. They believe her spirit has finally been put to rest. But Tun is still haunted. He discovers that the reason for his neck pain and his strange weight gain is that Natre's ghost is sitting on his shoulders.

Natre's ghost drives Tun to fall from a window. In the final scene, Tun is in a mental hospital, sitting still. A nurse sees his reflection in a window, and Natre is still sitting on his shoulders.

Who is the ghost in Shutter? Natre, a young woman Tun secretly dated in college. She was assaulted by Tun's friends while he took photos, and she later took her own life.

Why does Tun's neck hurt? Natre's ghost has been sitting on his shoulders the whole time. Her weight explains his neck pain and his strange weight gain.

Why did Tun's friends die? Natre's ghost drove them to suicide as revenge for assaulting her.

What happens to Tun at the end? He is in a mental hospital, and Natre is still clinging to his shoulders, a punishment that will never end.

Who was the woman they hit with the car? The film suggests it was Natre's ghost, already appearing to Tun and setting her revenge in motion.