Bai Jin is the younger brother Bai Yin, and the two chinese siblings travelled together learning alchemy and puppetry. After being left heartbroken when the target of his affections chose his brother instead of him, Bai Jin fell into madness and enacted vile actions that would create a chain of tragedy for hundreds of years.
He is the creator of the automatons and the Zonapha syndrome, thus making him the catalyst of all the major evils of the series and the main antagonist of Karakuri Circus.
Bai Jin was a fair skinned young man of average build with long black hair. He used for the most part a set of brown robes that covered most of his body, a more dark greenish hood over his clothes. Underneath he used to wear black pants and darkened shoes.
As he became older by 9 years, Bai Jin had a more crazed appearance. His maniacal appearance is far more exacerbated on his late years as an old man.
Bai Jin was initially shown to be an easygoing, expressive, polite and cheerful individual. Whatever positive traits he may have, however quickly banished once he learned his love was unrequited and fell into deep madness.
Maniacal, self-centered, uncaring, sociopathic, insane and completely detached from any ounce of sympathy, Bai Jin became a miserable man devoid of any ounce of morality or full of anguish, despair, sorrow and grew to become increasingly evil over time.
Desperate for affection he would not only kidnap Francine, but also hurt her physically and break down in tears afterwards, showing his unstable state. As Francine would never return the love he had for her, he grew more isolated and more somber.
As years passed his obsession would Francine would be made manifest when he created Doll Francine, purely to have "Francine" as his wife at last. When the automata failed to act like Francine, he became even angrier and more desperate and even resorted to a psychopathic display of genocide by having his automatons murder the townspeople and toy with their bodies, only so she could laugh for his sake, showing how far and beyond his humanity has been lost.
Even as he nears death, his obsession would only grew stronger and would enact a plan that would allow him to reincarnate in order to further pursue his mad agenda of making "Francine" and eventually any of her look-alikes to love him.
Bai Jin and his older brother, Bai Yin, traveled from their hometown in china, to learn alchemy and puppetry. Originally, their idea was to make a puppet move like a human, to do this, they sought to learn the art of alchemy. It was in France that the two met a girl called Francine. Bai Jin was the first to fall in love with francine, giving her food and other supplies. The affection was evident, as the young lad had no problem to do anything Francine suggested.
A bright morning, the trio headed out for a festival. The idea was that Francine wanted to go see the puppets, as she explained that she was fascinated by them. This reminds the two brothers of their own joy as puppeteers. While watching a show, Jin gives Francine bread, which she is later known to take to her brothers and sisters. The trio then come upon the puppets that Francine so wanted to see, but find that the stall is closed, with an old man managing it horribly. Instead of going home sadly, Francine suggests that the two, Jin and Yin, could do the puppets for him. Falling victim to his crush's idea, the two ended up doing it, amusing kids that walk by, and the day is a success. The two brothers drinking and enjoying at the end, Bai Jin appears to have drunk too much so his brother lays him on the bed.
It is then that Yin offers to walk francine to her door. In that timeframe, Yin learns about Francine's "family", and about her having the mark of a thief. He also learns that francine is a great person, helping orphans and the disabled ones. The next day, when Yin and Jin are home, Yin asks a question which would pertain to love, and walking the road to the world with someone else. Jin, now worried and possibly suspicious, asks if he talks about Francine. Jin cries that he loved the girl first, making his older brother uncomfortable. After that day, for a time, Jin doesn't talk to Yin.
A bright day, Bai Yin, goes to the church where he meets Francine. Seeing her pray for those who are misfortunate makes Bai Yin wanting to help Francine, decides to propose to her. Francine accepts and the two now-lovers hug and kiss. But as they walk out of the "empty" church, they don't realize that Jin is right there, his head touching the chair in front as he cries, as his rage is manifested on his inner demons.
That night, a possessive Jin kidnapped Francine and left the town so Yin decided to go after them. While traveling Jin would beat Francine into following her, to which he complied, but she wouldn't smile for him or love him as he truly wanted, instead she would cry at the man's miserable state. During the 9 years before Yin would find them, Francine and Jin would settle down in a castle in Quiberon. In that time Francine and Jin grew distant with one another to the point that Jin allowed the villagers to imprison Francine after she got sick. Jin would use research the means to get the Aqua Vitae in order to heal her.
Yin finally finds Jin and confronts him about kidnapping Francine. Jin then reveals he overheard their proposal in the church which is why Jin kidnapped Francine. With mild guilt Yin agrees that what he did was improper but then realizes that Jin has changed and become more crazed. Jin tells his older brother than Francine is sick and imprisoned in a cell.
Running to see her, Yin would exchange words with her for nine years. Trying to heal her, Yin also settles in the castle and the brothers would attempt to develop Aqua Vitae separately. The two brothers succeeded but it was too late, for the fearful villagers would set the cell on fire. Yin would attempt to rescue Francine but she opted to remain burned alive. Having met the love of her life again fills her with joy and without any regrets as she passes away.
The two brothers talk one final time when Jin claims Francine never loved him no matter what. Yin counters that she did in fact held some affection for him, else she would have tried to escape which she didn't. With all that was left of Francine was a strand of hair, the two brothers split, never to meet again.
While Yin would travel the world and reach as far as Japan, Jin would remain in Quiberon, spending several years attempting to recreate Francine as an automata to serve as his bride for once. With the mechanical body, a sample of Francine's hair and the Aqua Vitae he held, the Francine Doll would be born.
Although rejoiced at having his "crush" back, there was a major problem, although the Francine Doll was loyal to him, she would be unable to smile. This in turn made Jin a circus of automatons to make her laugh. Given to his mad impulses he would have his automatons perform a genocidal performance on the townspeople while spreading the Zonapha Syndrome as revenge for their mistreatment of the real Francine. When the Doll would still not smile, he would angrily chastise her as he was taking revenge on "her" behalf. While strangling her, he calls her the "Doll that isn't France" and discards her, taking her for dead, he leaves to wander alone. In truth, Francine Doll survived.
As he wandered alone, Bai Jin came to a realization, that he could remake a real Francine for himself by using Aqua Vitae and the hair of Francine that was in the Francine Doll, however, he was already too old to return to Quiberon to retrieve the Doll. Finding a nearby dog, he would have it drink Aqua Vitae mixed with his hair, and give it an order, to have a young boy he kidnapped drink the Aqua Vitae after he infuses his own soul in the Aqua Vitae, so that the young boy would become his new vessel to continue in his mad quest to have Francine for himself.
The plan is successful and the boy with his hair turning silver would inherit all of Bai Jin's memories and personality. Using his newfound body he would chase after the remnants of the Francine Doll as his newest incarnation, that of Dean Meistre.