Migi Kira

Migi Kira is a 2016 horror anime based on the serial killer named the Ningyo Killer, who forces individuals through pain to survive or save others.

Plot
A victim is seen strapped to a chair with knives going through his hands and legs, and a tape recorder tells him he must press his face into a knife in order to break the chair and escape. The victim did this and escaped, however was then tasked to walk on glass barefoot to reach the exit however fell and accidentally slit his throat, killing him. Meanwhile, a woman named Ayumi Hadzuki is seen and is shown to be one of the protagonists, and it is revealed her brother was killed by the Ningyo Killer (who was burned to death and revealed he murdered someone).

Meanwhile, a father named Minato Ito is taking his son Saito out on his birthday however he was abducted at the park so he tried to find him desperately but when he arrived somewhere, he was greeted with a box. It contained a phone, a loaded gun and five animal puppets. He broke down and cried at this tragedy, desperate to find his son, he took the box home to find clues. The police then investigate the recent murder of the Ningyo Killer case which is being led by FBI agent Ryota Takahashi, who discovers two tape recorders that informed the victim he was chosen because he was a drug addict and of his tasks, which were collected as evidence. Ryota further investigated the murder and discovered a message reading "LOOK CLOSER", so Ryota removed the part of the ceiling and found a box containing photographs of the victim and a third tape recorder: claiming the killer knows they found the body and more will turn up if people choose to make bad decisions.

Then a private detective named Takumi Yammato is also investigating the case and questions several relatives to thee victims, hoping to gather some information and discovers one of them received a letter containing photographs of some animal puppets and a phone provided to her tasking her to go to a warehouse.