AI: The Somnium Files Wiki
AI: The Somnium Files Wiki

Parasitism is a concept introduced in AI: THE SOMNIUM FILES.

Parasitism refers to the transfer of "consciousness" into a host body, like a parasite, and vice-versa, resulting in a "consciousness-exchange." When two minds are connected synaptically, such as through the Psync Machine, they are capable of performing an exchange, where both consciousness swap bodies. A parasite is capable of retaining their own memories, while also being able to collect fragments of their host's memories.





Known Parasites and Hosts[]

Parasite Host
Saito Sejima Rohan Kumakura
Shoko Nadami
Renju Okiura
Iris Sagan (Branch A)
So Sejima (Branch A)
Shizue Kuranushi/Boss (Branches AAA and AB: Ota Route and Annihilation Route)
Hayato Yagyu (Branch BB: Resolution Route)*
Kaname Date/Hayato Yagyu Rohan Kumakura
Saito Sejima
Shizue Kuranushi/Boss (Branch AB: Annihilation Route)
Rohan Kumakura Hayato Yagyu
Renju Okiura (Branch BB: Resolution Route)*
Shoko Nadami Rohan Kumakura
Renju Okiura Shoko Nadami
Iris Sagan Renju Okiura (Branch A)
So Sejima Iris Sagan (Branch A)
Shizue "Boss" Kuranushi So Sejima (Branches AAA and AB: Ota Route and Annihilation Route)


  • When describing his reasons to murder his host victims, Saito Sejima seemingly suggests that a parasite consciousness is able to imprint their own memories into the host bodies. Saito states that he kills the various people with whom he performs the consciousness-exchange because they would be capable of having Saito's memories of his past crimes, needing to keep them quiet in order to avoid his secret from being released.
  • According to the game's creator, Kotaro Uchikoshi, a person with Dissociative Identity Disorder (wherein a single body possesses multiple personalities that can alternate) is able to hold all personalities inside a body, and would have all of their personalities swapped into a body in the event they experience Parasitism.[1] This suggests that, within the universe of AI: THE SOMNIUM FILES, different personalities count as part of the same "consciousness".