Kuriba Ryouko

Kuriba Ryouko (操歯涼子 (くりばりょうこ)) is a student of School District 20's Shinshikimi Middle School and the creator of Indian Poker.

Appearance
Kuriba Ryouko has vertically striped hair, alternating between light and dark from a dark stripe at the middle of her frontal fringe. She has yellow eyes, and a darker section across the right side of her face from when she was split apart. She primarily wears an outfit consisting of a lab coat over a school uniform, both primarily black and white.

While working alone in her room, she wears swirly glasses.

Personality
Ryouko displays a reluctance to get other people involved in her affairs. She is devoted to finding a way to save her mother, volunteering to being split in two as part of the cyborg experiment to gather data to accomplish her goal. She also does not seem to put much value on her life, saying as such with her goal having been fulfilled when facing the doppelganger and being willing to give up her own soul or life to satisfy it.

Ryouko has a tendency to accept sacrifice as a necessary condition to achieve something, such as spreading the Indian Poker to solve the doppelganger problem despite knowing it would cause chaos, and not making an exception with regards to her own life in negotiations with her doppelganger. The doppelganger, who inherited this trait, noted that she was a person who couldn't accomplish anything without doing so.

Background
When she was little, Ryouko was caught in a building collapse and only survived due to a lung transplant from her mother. Her mother had a weak body even before the incident and was far from healthy afterwards. Ryouko subsequently dedicated herself to research in Academy City in order to learn the cyborg techniques needed for her mother to make a recovery. However by the time she produced results, her mother collapsed. Having caught an infection from, her body was at its limit. The advance of the infection was delayed by drugs but doctors only gave her a year or two at most to life. Ryouko needed to develop cyborg replacements for her mother's infected parts, but was faced with an overwhelming lack of data for development and the difficulty of gathering data on all of the many body parts needed for the treatment.

In order to gather this data in the time she had left, Ryouko volunteered herself for a cyborg experiment run by the institution she was working with, in which her body was split in two and the missing parts replaced with machines to create two separate cyborgs. Acting as both observer and specimen, Ryouko planned to use the experiment to gather data on every part of the body. After a year living apart, the two Ryoukos were recombined into one, with no split personalities or rejection, and retaining the memories of the time split apart. While Ryouko wished to test the compatibility between the cyborg technology and the human body, the institution hoped to observe a possible side-effect - the creation of a "soul".

Ryouko subsequently learned of her doppelganger and warned the scientists of the potential risks, but she was ignored. At some point afterwards, in order to find a solution to the doppelganger problem, she created the Indian Poker cards which enabled people to record and view dreams, and distributed the method to produce them.

Dream Ranker Arc
Ryouko first appears in a Indian Poker card that Misaka Mikoto was using as she was searching for the Bust Upper card. Seemingly speaking to Mikoto directly, she speaks cryptically of the future and that there is a threat that not only Mikoto cannot ignore, but also a threat that could lead to another one if Mikoto eliminates it. Before Mikoto could confront her, she appears to split into two.

Mikoto later meets two "Ryoukos" for the first time after the Electromaster was asked by Shokuhou Misaki to investigate on Ryouko's background. The first Ryouko, which was entirely mechanical, escaped from her facility by jumping from the topmost floor (and surviving). Meanwhile, the original Ryouko is later tracked down by Mikoto in an apartment complex with the help of Misaki. Although hesitant to cooperate at first, the original Ryouko eventually agrees to explain her involvement with the "soul creation" experiment and the development of the Indian Poker cards.

Once she completed her explanation, she left the two and went to collect her prescribed Miahilin. She considered getting Mikoto's help but decided against it, thinking that the situation would be resolved in time and she shouldn't involve others unnecessarily. She was then confronted by the doppelganger who had tracked her through her prescription, but managed to escape from her doppelganger's grasp using a countermeasure she had prepared beforehand. After escaping from the doppelganger, Ryouko was caught by Seike but was saved by Mikoto who confronted the Scavenger operative as she escaped.

At her apartment, Ryouko transferred her research data, so that her mother would be saved regardless of her fate, before setting out in order to resolve the situation. Reaching the area where the doppelganger and Mikoto were fighting, Ryouko told the doppelganger she wished to speak with her and was brought about the data storage airship. She described the Indian Poker and her efforts to find a way to erase a soul, offering to erase her own soul so the doppelganger could have her human body. When the doppelganger told her she didn't want Ryouko's body but wanted her gone and told her to kill herself if she wished to help her, Ryouko replied that with her goal of ensuring her mother's survival fulfilled, it didn't matter what happened to her, and let go of the airship. She was caught by Scavenger who had returned to aid Mikoto. Afterwards, Scavenger decided to discretely drop her off with their client.

After Mikoto's battle with the doppelganger concluded, Ryouko arrived at the scene by car, together with the project head, who was dismayed to see the doppelganger critically damaged and the data storage airship destroyed. Unable to accept that the doppelganger didn't have a soul after all, the project head held Ryouko at gunpoint to threaten Mikoto into salvaging the doppelganger. Ryouko tried to convince him that they should not trample on the doppelganger's dignity any further, but the gun went off as she was doing so and she was shot in the abdomen. While the project head ran off, Mikoto tried to aid the collapsed Ryouko. As she was doing so, the dying doppelganger remarked on her original being lucky to have suitable cyborg replacements for her damaged organs nearby.

Parts from the doppelganger were successfully used to save Ryouko's life. Afterwards, she began to see the doppelganger in her dreams. Initially she thought it was a hallucination brought on by her guilt, but the doppelganger in her dream had an accurate record of her battle with Mikoto, something which Ryouko herself didn't know. When Ryouko asked if this was a chance for her to apologize, the doppelganger told her that she wasn't trying to kill her over a grudge but as a necessary condition, noting that accepting that sacrifice as such may have been an influence created from Ryouko's thought patterns, describing how Ryouko spread Indian Poker despite knowing it would cause chaos in order to save her mother and didn't make an exception with regards to her own life. While noting that Ryouko was a person who couldn't accomplish anything without sacrifice, the doppelganger told her that there was no need to reject who she was, as she would become someone who would harm nothing but also create nothing, which would make sharing her life boring. Since then, the doppelganger kept appearing in her original's dreams and pointing out points for correction in her research. Ryouko described the situation to Mikoto when she came to visit her in hospital, apologizing to her for forcing the responsibility onto her and telling Mikoto how the doppelganger seem to be the most fulfilled in her battle with her.

Abilities
Ryouko is a talented intellect in the field of cyborg research, knowledgeable and intelligent enough to have devised a number of the technologies which were used for her cyborg body, as well as countermeasures against them. She was also capable of devising multiple methods for Indian Poker from readily obtainable tools.