He seemed to just appear one day, but no one knows exactly where from (well, no character in the roleplay does, anyway); he had simply seen them one day and followed. Most everything about him, his true personality and true motives, are a complete mystery as of yet to everyone but himself. All that is certain thus far is that he likes to sleep and tends to be a bit of an ass for what appears to be no reason. He also seems to have no trouble deceiving, as the person he displayed himself to be was a complete lie. Nobody's really bothered to ask about what happened to him before he met them nor has he said much about his past.
Until he was about 16, Kainashi lived with his parents, Sabitsuki and Ritsu in a joint custody due to the fact that they were never married. However, he has never been particularly close to his mother. Sabitsuki, too entrenched in her own subconscious exploration, nearly always neglected and ignored him. She was never afraid to go out of her way to alert him of the fact that he was absolutely not wanted by her, and that he was an ugly, worthless human being. That is where his name, Kainashi originates from, meaning "worthless" in Japanese. His father, Ritsu, was much kinder to him; he celebrated his son just as he was (though he may have influenced Kainashi's feminine wardrobe a bit...). To alleviate Kainashi's suffering, Ritsu installed an UTAU panel into his son's back at about the age of 7. It was much like surgery, but now the entire foundation of Kainashi's back, including shoulder blades and spine, is mechanical. Kainashi does not remember the process at all, most likely because he was knocked out much like a human surgery. As a result, Kainashi considers himself to be a living synthesizer, because he sees nothing else very interesting about himself.
When Kainashi was around 9 or so, he began wandering in abandoned buildings near Sabitsuki's apartment, tired of sticking around in a home where he was not exactly wanted anyway. At the age of 10, he made the grave mistake of exploring his mother's old schoolhouse, where he had an unpleasant encounter with the only friend she's ever had (or at least mentioned), a man only known by the nickname "Smile". That day, he was violently raped and has the scars to prove it. On the roof of his mouth, he has a pronged scar inflicted by Smile's hammer. Most of the cuts he received since then have closed and healed, but one on his left clavicle-area and one on his right shin have still not healed completely; they were also very deep, so it's unlikely they ever will heal. At that age, he was unable to comprehend the shame and defilement of such an act, he only remembers great amounts of pain and blood. He did not understand the secondary psychological scars until his father explained to him what rape is, likely a bad decision on Ritsu's part. Upon the discover of her son's experience, Sabitsuki was rather indifferent to it. She showed no extra sympathy to him and did not try to help him grow and accept the experience. Because of this, Kainashi has taken to pretending the incident never happened, though not harshly or desperately. He chooses not to consider it unless someone reminds him. Despite the fact that it did, indeed, happen, he has no dysfunction surrounding physical touch, sexual urges or the slightly flirty outfits he chooses to wear. The only way one would be able to tell he was a victim of rape would be for one to force the story out of him by proving they knew it happened.
Kainashi has also developed a minor eating disorder, choosing only to eat one square meal a day (plus the occasional snack) in order not to gain weight due to his very unhealthy diet.
After that, he suffered even more than before for six years, Sabitsuki's neglect only crescendoing into utter ignorance to existance and even Ritsu's love for him starting to look fake or exaggerated. He also developed a crush on his father's best friend, Ruko at age 14. He never told anyone and let the crush rot, crumple and die inside him without ever being realized. At age 16, he dropped out of school and simply ran away from both of his parents, only letting Ritsu know through e-mails and texts. Ritsu has not seen his son face-to-face in about two years, and is very worried. However, he has made no known efforts to come find Kainashi.
For two and a half years, Kainashi drifted from town to town, even moving to America in hopes of finding anything new. He hasn't lived in a permanent home for that entire time, he's only taken shelter in different towns. As a result of the long abuse he's received his entire life, he suffers from severe PTSD, as well as a fun gallimaufrey of other mental and emotional scars. He does not deal with these issues gracefully, to say the least.
Relationships with the other Mistakes
Kainashi is a highly solitary person. So far, he has spent most of his time sleeping (for whatever reason), or pestering Rowan. His relationship with Rowan is perhaps the only key to solving the puzzle of who he is, because not even after confessing that he had lied about his real self do any Mistakes know for sure who he is and why he does the odd things he does. He thinks of Rowan as the only Mistake who is his equal, though he is mistaking a feeling of deep romantic love for a sense of shared humanity. Kainashi would never admit how he feels to anyone, because he does not realize it yet. Because of his aggressive loyalty to Rowan, displaying itself rudely and sometimes even illogically, none of the other Mistakes have given him a chance yet.
Despite the horrible act done to him in conscious reality, Kainashi has formed a near-exact replica of Smile in his subconscious. dream!Smile as he is called, though, has seemed to develop a mind of his own. He began long ago to rebel against the label and role Kainashi expected him to fill, that of the Devil and the Mental Obstacle, and has earned Kai's friendship and trust over a careful build-up of a year or so. While still very unnerving and crude, dream!Smile in fact has nothing but good intentions, and is extremely protective of Kainashi. They are, oddly enough, the best of friends, perhaps even platonic soulmates. While he does not exist in waking consciousness, dream!Smile is very real in true reality. He and Kainashi meet every night when he sleeps, and go on all sorts of interesting !!Dream Adventures!! together. He... Seems to place an odd priority on potassium in Kainashi's diet, though.
At first, Kainashi showed himself as a constantly sleepy, deliriously happy and actually quite cuddly person. Everyone believed him at the time (except for Yuuka and perhaps Kyle), so he saved his second layer of personality for only himself. On the night that he and Rowan kept watch over the frozen Kurgan Junior, he shared his true self; quite the judgemental and manipulative little bastard, very fond of mind games. He was able to keep up the facade for another day or so until he had verbally slipped up too harshly in front of the rest to keep lying. In reality, Kainashi himself is unsure if the second personality is who he is, though he would never admit this to anyone. He presents himself more accurately in his subconscious.
As a result of the neglect and abuse he faced as a child, Kainashi developed a four-layered thinking process to cope. He has not yet shared any specific evidence of abuse with the Mistakes in fear of being judged for it or ridiculed for being as weak as he was. He is sure that more than four layers exist, though he's only identified four. The layers are as follows:
Layer One: Sleepy - This is the personality shown to the group at the very beginning. Kainashi later claimed to use this persona because he believes that people naturally like those who are happy and cuddly and innocent. The voice of Sleepy is as one would expect, very soft and airy; it sounds both there and not at the same time.
Layer Two: Grumpy - This is the personality shown to Rowan primarily, then to the rest of the Mistakes after an accident regarding his, er, "acting" skills. Grumpy is the before-mentioned manipulative little prick who enjoyed himself a good mind game. He enjoys talking people in circles. The voice of Grumpy is solid and deeper than Sleepy's, and he is said (in meta) to have a wonderful singing voice.
Layer Three: Pattern-Breaker - The name of this personality is exactly what it says; it breaks the pattern of the Snow White-themed names he had come up with because it really does break a pattern in his thought. Pattern-Breaker is the representation of Kainashi's bottled-up emotions from his childhood; Pattern-Breaker acts like a scared child in its reflection of this. Pattern-Breaker showed himself to Kyle once, but only for a brief moment - when he apologized over and over after being hit by Newt's stun gun.
Layer Four: Liar - The name of this personality is in itself a lie; Liar is the only truthful persona of all the identified layers so far. Liar illustrates Kainashi's ultimate desire to be loved like everyone else; while feeling very cliche in the process, Kainashi deeply envies the unconditional love the Mistakes have for each other and resents that he and Rowan cannot have it as they are right now. Liar is the most pleasant of the personas, and arguably the true Kainashi, or the man Kainashi wishes to be someday.
Layer Five(?) - Dancer - This personality only appears in Kainashi's subconscious. It represents all of the pride, sex appeal and arrogance inside him. Dancer acts like a matronly drag queen, to use a rather odd example, referring to everyone as "honey" and ruffling up their hair. He seems to enjoy being kissed on his hand. However, Dancer appears somewhat infrequently in Kai's subconscious. The personalities to appear more in Kai's subconscious are Layers 3 and 4, or a mixture of 2 and 4.