AI: The Somnium Files - Nirvana Initiative

Story

Six years ago, the right half of a corpse was discovered under mysterious circumstances. The left half was never found... until six years later, when it was discovered completely fresh and with no signs of decomposition, as if the victim had been alive until recently. Now newly appointed special agent Mizuki and her AI partner Aiba are tasked with solving the bizarre serial murders of half the corpse...