Yomiko is a paper master, a human whose connection to paper and written word is so strong that it allows her to bend and mold paper to her will, almost to the point of changing its structure. In her hands, paper can change into a bladed weapon, projectiles, shields capable of stopping bullets and more. Her powers also have creative applications, such as creating larger-than-life, functioning paper airplanes that she can fly around in, and stairs to bridge gaps she cannot cross. Furthermore, her ability to manipulate paper is only hindered when the paper in use becomes completely submerged and soaked in paper or is burnt away to nothingness.
Half Japanese, half British, Yomiko was enlisted by the Library of England Special Operations Division when she was in her teens. (In the R.O.D. universe, England has remained a superpower and the Library of England serves not only as a library, but as a political organization.) Under the supervision of Donnie Nakajima, the 18th generation paper master, she trained to become a library special operations agent, specializing in retrieving and verifying stolen texts and ancient manuscripts, all under the supervision of Mr. Gentlemen, a man who was secretly an ancient being who had been manipulating the direction of humanity's evolution since near the beginning of time. She was praised by her superiors for having the promise to surpass all paper masters before her and quickly became the 19th paper master following Donnie's suspicious and manipulated retirement. Unbeknownst to her that her beloved mentor's withdrawl from the Library Special Operations was machinated by Mr. Gentlemen and his second-hand man, Mr. Joker, Yomiko took up the mantle of "The Paper" and began working cases for the library, substitute teaching literature while not on assignment. She moved from England to Japan, in the prefecture of Jinbocho, known for its wealth of book shops, buying a building that quickly became little more than a "book box," storing Yomiko's personal library... that she just happened to sleep in.
Over the course of her tenure with the Library of England, Yomiko developed several meaningful friendships with fellow agents and related bibliophiles. Most notable amongst these relationships were Nenene Sumiwagara, a teenage author with a penchant for getting herself into trouble, Drake Anderson, a mercenary former employed by the American special forces, and Nancy Makuhari, a fellow special agent with the ability to phase, or "dive," through solid matter, earning herself the codename "Miss Deep." It was because of Yomiko's relationship with Nancy that she ultimately left the service of the Library of England.
Nancy fought alongside Yomiko against the agents of the I-Jin organization, a society comprised of people who had been cloned from the DNA of the best and brightest members of humanity. The I-Jin's goal was the wipe out humanity and begin the race anew, spearheaded by none other than themselves and other genetic samples they had accumulated. While the two had created a bond of close friendship, Nancy neglected to inform Yomiko that she herself was an agent of the I-Jin, cloned from the famous spy, the Mata Hari. Nancy was following orders from the head of the I-Jin, her lover, Ikkyu Soujun to accompany Yomiko in recovering a set of books that would allow them to fashion a song that once heard would drive the listener to suicide. However, Ikkyu found Nancy too free willed for his purposes (or her friendship with Yomiko made him question her completed subservience to him) and so he cloned Nancy again, succeeding in a new model that worshipped him. During the final conflict, Nancy perished alongside Ikkyu, however her clone survived, albeit suffering amnesia due to oxygen deprivation after nearly drowning. The clone was relocated to a nursing facility where she would be cared for, and should she ever recover her memories of the event, stand trial for her crimes against humanity. Before passing, Nancy requested that Yomiko care for the clone, referring to her as her "younger sister." And so Yomiko created a new friendship with clone-Nancy, acting both as friends and sometimes mother to her.
During clone-Nancy's stay with the facility, she gave birth to a child fathered by Ikkyu, a boy dubbed "Junior." The child was found to possess the diving ability that both Nancy and her clone had possessed, and so Mr. Joker took the child into his custody, citing Nancy an unfit mother due to the childlike mentality she'd adopted after her near drowning. In time, Yomiko spoke in clone-Nancy's defense, demanding to know why the child would not be returned to his mother. Mr. Joker refused and openly mocked Yomiko for her complete ignorance regarding the situation the Library now found itself in. Namely, Mr. Gentleman was finally dying and would be leaving the world without his wisdom and guiding hand. Mr. Joker had stepped forward as leader of the Library as Mr. Gentleman's status degeneration, stating his ambition to create a world free of poverty and ineducation, where all would flourish and to accomplish that, he needed Nancy's child. Unable to agree with Mr. Joker's extremist measures, Yomiko protested, and Mr. Joker informed her that if she would not assist their directives as an agent, then she would no longer be necessary to them, and to prove the lengths to which he was willing to go to make his dream a reality, informed Yomiko of a grim truth: Donnie Nakajima, Yomiko's former mentor and lover, had been incapacitated by his former employers. When she learned of Donnie's fate, Yomiko was unable to control her emotions and the chaos in her heart created a reaction in the books in the library, causing it to literally tear itself apart. Yomiko fled, but not before seizing one of the key items necessary to Mr. Joker's plans, taking it and Nancy and going to ground, not to be seen by anyone for four years.
Ultimately, Yomiko was flushed out of hiding by Nenene Sumiwagara and the Paper Sisters Detective Agency, Michelle Chang, Maggie Mui and Anita King. Following them, Mr. Joker also located Yomiko and clone-Nancy and demanded that she return a piece of property she had absconded with while fleeing the Library of England: a book containing a portion of Mr. Gentleman's memories needed to create a new Mr. Gentleman to direct humanity. In preparation for Mr. Gentleman's rebirth, Mr. Joker and his subordinates had created libraries in countries all over the world designed to act as storehouses to unify and educate the "ignorant masses" as well as give the Library of England control over the regulation of information and education all over the world. Despite her best efforts, Mr. Gentleman's book fell into Mr. Joker's hands and he nearly succeeded in transferring Mr. Gentleman's psychi into the body of Junior. Only through the combined efforts of Yomiko, clone-Nancy, the Paper Sisters, Nenene and Drake Anderson were Mr. Joker's plans foiled. Together, they overtook the Library of England's base, destroying the resurrection apparatus and fleeing into the night.
As the world returned to its former state, Yomiko and Nenene traversed the globe with clone-Nancy, helping her recover her memories and accept herself, so that she could be a model mother to Junior. No longer forced to hide away, able to remain reunited with her best, truest friend, and able to read endless amounts of books, this made Yomiko very happy.
How long this happiness remained is a valid question.