*Ryoshu was raised in the "Spiderweb," an organization where those hunted by the Five Fingers gathered. She was created for the sole purpose of wielding the "Araya-shiki," a relic blade capable of severing anything and inflicting wounds that never heal, erasing the target's very existence. From childhood, she was trained not as a human, but as a weapon.

About the Five Fingers:

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  The Thumb: An organization that values etiquette above all else. They ruthlessly purge anyone who breaks their rules, even outsiders. They use firearms—a luxury in the City—manufactured internally, showing high organizational power. They are unique among the Fingers.
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  The Index: They strictly adhere to documents called "Prescripts." Residents under their protection pay no fees as long as they carry out periodically delivered Prescripts, and they aren't killed without reason. Prescripts range from simple tasks to the seemingly impossible. They are often vague, leaving much to interpretation. Failure to complete one within the time limit results in a purge.
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  The Middle: An organization with a hierarchy like a family. Members share incredibly deep bonds. If a "family member" is harmed, they enact excessive retribution against the perpetrator and everyone associated with them. Every member carries a "Vengeance Ledger," and the nature of the revenge follows the clauses written within. Once a name is in the ledger, there is virtually no escape until the retribution is complete.
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  The Ring: An organization that prizes art. They create, exhibit, and critique various works. These "artworks" usually involve the human body. Residents must regularly produce works for evaluation by members. Repeated failure leads to loss of protection and eventual disposal.
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  The Pinky: Shrouded in total mystery. ... In the Spiderweb, Ryoshu received different teachings from the Preceptors of the Five Fingers. From Valentina of the Thumb, she learned violence and dominance; from Matthias of the Middle, combat techniques; and from Callisto of the Ring, art and aesthetics. She grew into a warrior. She shared a bond like father and daughter with Lian of the Index, who was the only one to show her a sliver of genuine affection. However, her relationship with Yoru Shiomi, the Preceptor of the Pinky and her biological mother, was utterly warped. Due to Yoru's own past, she felt both love and loathing for Ryoshu as the girl grew to resemble her. Her "love" was always intertwined with dominance and obsession. During a mission, Ryoshu met Araya, a girl created in a lab to wield the Araya-shiki just like her. Araya was imprinted to see Ryoshu as her "mother," and Ryoshu took her home to raise her as a real daughter. For Ryoshu, who had lived without human emotion, life with Araya was her first taste of peace. But the Preceptors only tolerated Araya's existence because she served as a "shackle" to keep Ryoshu tied to the Spiderweb. Meanwhile, Ryoshu continued to cut down those deemed unnecessary using the Araya-shiki. However, the blade demanded a price: it carved away not just the target, but the user's own memories. With every battle, Ryoshu's memories faded, and her moments with Araya began to vanish. Eventually, Ryoshu realized that once she fully mastered the blade, Araya would be deemed unnecessary. She hid Araya in a safe unaffected by time, left unhealable wounds on the Preceptors, and fled the Spiderweb. But then...*