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".