The Perfect Insider: Setsuko Gido

A magazine reporter who comes to investigate the mystery on the island.  

The Perfect Insider: Shiki Magata

Shiki Magata is an extreme genius computer programmer.  She was accused of murdering her parents when she was fourteen. She was found not guilty due to her psychological condition and claimed that a doll killed them.  She lives in a secure room in a research lab on an isolated island.  For fifteen years she stayed in a room that no one else ever entered and she never left, she was in there when the murder occurred.