AI: The Somnium Files – Nirvana Initiative

AI: The Somnium Files – Nirvana Initiative, a 2022 visual novel adventure from Spike Chunsoft, picks up after the events of its 2019 predecessor. The story follows a grown-up Mizuki Date and a new protagonist, Kuruto Ryuki, as they tackle a series of killings known as the "Half-Body Murders." Players navigate the game through visual novel segments and third-person exploration during dream sequences called Somnia.

Kotaro Uchikoshi, the writer of the first game, returned to pen the script, with character designer Yūsuke Kozaki also back on board. Akira Okada, who served as designer and assistant director on the original, stepped up as director. The game launched on Nintendo Switch, PlayStation 4, and Windows in June 2022 for Japan and North America, with a July 2022 release in Europe and Oceania. The Xbox One version was released later, on July 8, 2022, in Japan and North America.

The story unfolds six years after the first game. Mizuki Date, now an agent for the Advanced Brain Investigation Squad (ABIS), works with her AI partner Aiba—the same one that helped her adoptive father, Kaname Date. They investigate the Half-Body murders, a cold case from six years prior that has resurfaced. The narrative also follows the original investigation, led by ABIS agent Kuruto Ryuki and his AI eye partner, Tama. Both agents use a technique called "Psyncing" to enter suspects' dreams and extract clues.

In the Ryuki side, set three months after the first game's New Cyclops Serial Killings, rookie agent Ryuki attends a live quiz show interrupted by the appearance of half of Jin Furue's corpse. This kicks off the "Half-Body" (HB) murders, committed by a masked figure called "Tearer." Ryuki and Tama trace the killings to a group called Naixatloz, which believes in simulation theory and promotes the "Nirvana Initiative." Kaname Date joins the case, and soon other victims—geneticist Chikara Horadori, Naixatloz leader Tokiko Shigure, and comedian Andes Komeji—are found cut in half. When Tearer kidnaps Kizuna Chieda, a friend of Iris Sagan, Ryuki and Date plan a rescue. The rescue is a trap: Tearer tries to force Ryuki to kill Date. When Ryuki refuses, bombs detonate, costing Mizuki her left eye. Date, trapped under rubble, gives a broken Aiba to Ryuki before being crushed. Ryuki suffers a breakdown.

The Mizuki side takes place six years later.