Subete ga F ni Naru: The Perfect Insider

Subete ga F ni Naru: The Perfect Insider (すべてがFになる) is a Japanese 1996 mystery novel by Hiroshi Mori. It has been adapted into a manga, a visual novel, a Playstation game, and a live-action drama. An anime television series adaptation produced by A-1 Pictures premiered in Japan on October 8, 2015.

Plot
In a research facility hidden away on a remote island, genius programmer Shiki Magata has lived as a recluse for years. She rarely sees guests, but architectural-engineering associate professor Souhei Saikawa and university student Moe Nishinosono still seek her out. However, their meeting is cut short when they are caught up in a locked-room murder mystery.

Everything is not as it seems, and many secrets are hidden. Within an isolated facility, a seemingly impossible and gruesome crime takes place, and Saikawa and Moe must unravel the truth behind the murder and Magata's shrouded past.