I was hesitant on whether to put this here on the the flow board but it seemed more fitting here.
My theory is based on my first impressions of the game back when it was still in the earlier versions and how the game has developed, along with my theory. This is incredibly long and way too detailed and I will probably add more stuff later.
Sabitsuki was/is a creation of some sort. Her along with others were created for tests or even to be a separate race. Sabi was probably the first Perfect child created while everyone else was imperfect and put through more brutal tests. The main creator was the Doctor found in the clinic behind the Sugar Hole, while Oreko might have been a fellow worker/spy for him.
There are many types of children found behind his clinic, in which I classify in several groups. The first ones are the 'normal' ones with no signs of abuse and normal colored hair. These kids however are turned into the 'ideal' ones with white hair, however the transformation involves many forms of abuse, and while the stable ones are kept in one hall, the others are piled into another wing where they die or revert back. The ones that revert back or didn't transform at all are turned into Viscera girls.
The Viscera girls are seen in different areas in the game but are mainly found in Womb world. The doctor treated these girls more brutally than all the rest since they failed to transform, conducting more sanguinary test and mutilating their bodies completely. They appear to be unstable in form and would suddenly open up in sores and erupt in bloody sores. They mainly stand still and move seldom. There are several of these girls found in areas with the other children: one in the large white area where many of the kids walk in unison, one in one of the halls, and the event where one of the halls takes you to the Large erupted Viscera girl. However, the fact one of the halls is found behind the clinic with abused children and another is found in the Plant caverns with unharmed children leads to my theory about the last group of children.
As we can see, the doctor has a Nurse in his office, however there is another Nurse found in an open grass area that connects the Clinic with the Plant Caverns. This nurse has flowers growing on her, the main characteristic of the last class of children. This nurse possibly helped a number of the children escape from the test and most likely rescued Sabi as well judging from the Plant effect. However, either the unstable form of the children or the cavern itself caused plants to grow on the children, making them unable to leave the caverns. However those who didn't become one with the plants escaped with the help of the Flower girl found in the cavern.
The flower girl was seen in earlier versions of the game inside of a room in the apartments. She had Poniko type eyes and a flower on her desk, yet she also appears encased in Vines within the cavern maze. She may have been helping her, what I assume, boyfriend who is also suffering from the Caverns curse. He is seen within a small room in the caverns and gives you the Flower system type. Sabi and a few others were taken to live with her in her apartments after passing different areas and with some of the kids going rouge and becoming violent along the way. From the areas in Sabi's dreams, I assume they crawled through the sewers to get out of the caverns, arrived in a bleak city with light up signs, and trudged through snow.
Sabi and a few others were then enrolled in a school together where she was shunned for being considered superior by the Doctor. These kids are the Kaibutsu if it wasn't already implied and they eventually grew to embrace their violent. Sabi I presume, resisted her violent urges but upon suppression of her thoughts, she developed her alter ego, Rust. There is a certain Kaibutsu who shares very similar appearances with Sabi: the same hair and the same Steel Pipe. She is also seen in the school where you receive the Uniform effect, and is the Kaibutsu that goes after you in the Corrupt School event, which leads me to my theory about Smile.
As many people already see him, Smile is the tough guy of the school, however not the tough guy many people canonly portray. He appears to be head of a 'gang' at the school who have Tattooed eyes and hate the Kaibutsus who commit crimes and torment others. He is the Protector of the school I assume from his not only guarding his sister, but also a group of students in the school. During the events of the Corrupt School chase, Sabi enters the top floor and finds smile waiting with his hammer. This event can be interpreted two ways for me; Sabi was a victim in the chase, running from fellow Kaibutsu who deliberately led her up to the room Smile was in with her steel pipe, and Smile, seeing Sabi as a Kabutsu, attacks her. Sabi apparently doesn't want to hurt Smile either since she is Intimidated by him, idolizes him, or as others suggest, likes him. In this scenario, Sabi feels guilt for being associated with the Kaibutsu and sees the Kaibutsu chasing her as her alter ego Rust. In the other scenario she is being taken over by Rust and does indeed go on a rampage at school, only to be taken out by Smile.
As for Oreko, whom I mentioned earlier, she may have been the main creator of Sabitsuki herself. While the doctor did run the test and was in charge, Oreko was the one who actually created Sabi. Oreko can be seen as a friend of some sort to Sabi or as an obsessed Stalker. Up until the recent version, she was somewhat of a stalker from the fact she would stare at Sabi from her machine, come closer if you equipped the Helmet, and the fact she would hold hands with an abused clone of her. She does however have a 'friendship' meter since the recent release, which I see as more of an 'appeasement' meter. She is often associated with being underwater; however, this may be a result of Sabi having seen her from inside the water inside the test tube she was made in. Oreko most likely didn't want to part with her 'perfect creation' and created different Sabis for herself to either run her own tests on, or keep as a trophy of some sort. The Doctor probably found out about Oreko's creations and hired the 'Cleaners' to find and capture any Sabi that wasn't his.
The Cleaners appear in different areas in the game and can be interpreted in different ways, either as just maids or as deadly Hench men. Working both in secret and in the Sugar Hole, the maids team up with the Kaibutsu to take Sabi back to the Doctor. At the end of the game, the Cleaners find Sabi in her apartment and capture her. In the Rust ending, Rust completely takes over Sabi and the Cleaner takes her away and groups her with the Viscera Girls for becoming hostile. However, since that was just one Sabi, the true ending reveals that there is still another Sab roaming around.
Explicit Immature Content