Sabitsuki and Rust Theories

Theories about the protagonists of the game, Sabitsuki and Rust.


  • It is theorized that the shape on the title screen of .flow is a very abstract depiction of Sabitsuki herself.
  • If it is to be inferred that Sabitsuki, Smile, and Sister are all related the difference in hair color could be a side effect of the "cure" she and the other test subjects were given as all the Kaibutsu also seem to have white hair as well.
  • It is theorized that Sabitsuki is slowly losing her mind either from the disease or from side effect of her treatments.
    • The Kaibutsu also seem to have lost their mind as well (active chasing ones) or are on the verge of losing them (normal ones that will become active after hitting) which could further link that both Sabitsuki and the Kaibutsu are suffering the same disease/side effects from disease treatments.
  • Sabitsuki didn't fit in much at school and was either widely ignored or made fun of. Support for this theory is that going through the corrupted school Kaibutsu will actively chase you with pipes as they their laughter fills the halls.
  • The reason that Sabitsuki doesn't want to leave her room may imply that she is quarantining herself because of a disease that she has.
  • Sabitsuki may be a foreigner. Although it is easy to assume she is showing albinism, either from birth or due to a disease, it can also be to contrast her as a foreigner, possibly Caucasian. If the other 'infected' are a twisted portrayal of other Caucasians, it can indicate she has had serious trauma in her home country. Many of her effects, such as Tattoo and Gun, are heavily associated with Westerners (if not the Yakuza, which are also associated with guns and tattoos). Many Americans enjoy owning handguns for intimidation purposes alone, which matches up with Gun's function. In Japan, it is highly illegal to own a handgun, meaning they are less relatable. The Uniform effect is a pretty standard uniform for American private schools. Another aspect that supports this theory is that most writing that has appeared in her dream world is in English (for example, Sugar Hole), which is the most common language it would be in if her first language was English. This theory relies heavily on the concept that the dream world as well as everything that happens to Sabitsuki is a metaphor.
    • It is also possible to simply assume that .Flow takes place in North America, which is a popular setting for Japanese fiction.


  • There's a possiblity that Rust is the part of Sabitsuki that has become diseased.
  • Whatever powers gave Sabitsuki her effects may have been the same power that was keeping Sabitsuki and her world in stable, and Rust is the consequence of the disease progressing into its final stages. Whereas Sabitsuki was protected from damage when touching the red creatures and was guarded against some of the more corrupt places with only her effect deactivating, Rust is vulnerable to everything. The overall health of her world also begins to deteriorate, which is more evidence of a protective force disappearing.
    • Some theories, suggest that Rust is a violent split personality that Sabitsuki tried to suppress.