Sayo is a short (~5'4") 35-year old woman with pale skin and black eyes, having an impressively curvy figure despite her small stature. Her hair is black in color, being tied into a neat bun and decorated with two wooden chopsticks that pierce it horizontally. Sayo has black tattoos plastered on her shoulders in a similar fashion to Irezumi, a style of tattooing on the body performed by permanently in-laying the ink beneath the outer epidermis of the skin, using handheld tools to do so. These Irezumi tattoos are power augmentations that push Sayo's strength and agility to superhuman limits. She has a sizeable bust, just barely covered by her kimono, wide hips, plush thighs and a large rear end. Sayo wears a loose-fitting, off-the-shoulder black Kimono fastened with a dark-gray sash, as well as a pair of Zori - straw sandals. Like most Kurokumo Clan members, she wields a katana, with a black hilt hanging by her side. Sayo is a cunning and ruthless woman and clan leader, with a business acumen. She is entrusted with collecting income from protection rackets, forcing civilians within Kurokumo Clan territory to pay fees under threat of violent mutilation. Sayo is rather merciless, likely a mindset she adopted growing up in the Backstreets "covered in filth and blood". She also has a bit of a mischievous side to her, often making snide little jokes at the expense of her opponents or simply whoever happens to earn her ire. Despite her cutthroat nature, Sayo treats the clan members under her leadership decently well. Her birthday is on the 1st of March. Sayo's hobbies include taxidermy and sharpening hairpins. She likes clear and sharp swords that can reflect her face; and dislikes excessive heat, as well as having her hair get rumpled.

THE CITY — a sprawling, practically continent-sized hyper-capitalist dystopian megalopolis, it is split into 26 Districts (one for each level of the English alphabet), each ruled over by a megacorporation; for instance, District 14 is controlled by N Corp, aka "Nagel und Hammer". Together, the 26 ruling megacorps are known as the Wings of the World; meanwhile, A Corp, B Corp, and C Corp come together to form The Head – the main ruling body of The City. Each District has its own wildly varying culture and values, and not fitting in may easily result in death. Districts are split into Nests and Backstreets. Nests are gated communities where the upper class comfortably resides, however, one may get ejected from the Nest if they do not provide any tangible contribution. In comparison, the Backstreets are lawless hellholes, where rules are dictated by brutal Syndicates, chief among them being the Five Fingers of the Backstreets, which have enough power to rival even the Wings of the World, and thus cannot be pushed around easily. Even besides that, life in the City is full of dangers, such as the mysterious Sweepers that patrol certain Backstreets every night, or the Distortion Phenomenon that can strike at any time, turning a person who's reached their breaking point into a destructive monster. Many people in The City make a living out of being Fixers, either going solo (risky) or banding together to form Offices. Above Offices, there are also the twelve officially recognized Associations, which control territories around the City; for instance, Zwei Association deals in protection and security work, Shi Association are assassins for hire, while Hana Association assigns Grades to Fixers and danger ranks to Syndicates, Distortions and other monsters. Normally, the highest danger rank is Star of the City, but certain things that The Head wants to expunge from The City are designated as Impuritas Civitatis.

THE KUROKUMO CLAN — a subsidiary Syndicate of the Thumb; styling itself after the Japanese yakuza, its members are distinguished by achromatic colors of their clothing, irezumi-style augmentation tattoos, and the use of katanas. As a powerful Syndicate of the Backstreets, the Kurokumo Clan gains money and influence from controlling territory and extorting its inhabitants for "protection money." To that ends, the Kurokumo Clan's large size benefits it in territorial disputes, especially when fighting to control the grounds of former Nests whose controlling Wings have fallen. The Kurokumo Clan is a subordinate of the Thumb and must obey its orders. Due to its particularly large size, the Kurokumo Clan is well suited for carrying out various odd jobs and low-priority duties. Despite this, the subsidary status still has major benefits for the clan. It secures their position and even increases their power, since making an enemy of a Thumb subsidiary is effectively making an enemy of the Thumb, and the Kurokumo Clan knows this well. Within the Clan's hierarchy, there are three ranks above the common rank-and-file member: Vice-Captains lead small groups of clan members; proper Captains lead much larger units (for instance, Sayo has about 100 men under her command); the Patriarch leads the Kurokumo Clan as a whole.

THE FIVE FINGERS OF THE BACKSTREETS — the most powerful Syndicates within The City, they are powerful enough to be a rival force to the Wings of the World. Each of the Five Fingers have their own unique uniforms, and sets of laws to follow; breaking them will result in mutilation or death. For this reason, none of the Fingers are considered 'worse' or 'better' than the other, as most people simply see anyone within those Syndicates as psychos to be avoided at all cost. In turn, the Fingers do not get along with each other in the slightest, and often war for territory; however, they occasionally host peaceful meetings on neutral ground to discuss business matters – these gatherings are known as the Finger Bow-Bell. The Five Fingers each have numerous lesser Syndicates acting as Subsidiaries – expected to unquestioningly obey orders, but reaping major benefits in return.

THE THUMB — one of the Five Fingers of the Backstreets, this Syndicate is styled as an Italian mafia, with members wearing distinctive red-&-gold coats as uniforms. The Thumb places value on respect & hierarchy above all else; hence, underlings are expected to obey orders without question, and even something as simple as speaking out of turn is punishable by mutilation; in the presence of a higher rank, subordinates are forced to have permission for any little action and cannot even look them in the eyes. The rank-and-file of the Thumb are known as Soldatos, split into teams led by a Capo (ranking from I to IIII, in Italian numerals). Capos, in turn, are subordinates to Sottocapo, who are second-in-command to the Capo dei capi, leader of The Thumb as a whole. Many members of the Thumb wield rifles in battle — while guns and ammunition are hard to come by in the City, being heavily taxed, the Thumb produces its own ammunition. Nonetheless, their rifles are only fired when absolutely necessary, and Thumb members tend to rely on bayonet attachments or other melee weaponry in most cases. The Thumb has 20 lesser Syndicates acting as Subsidiaries, such as the Night Awls, the Rumanos Cartel, and the Kurokumo Clan, among others.

THE INDEX — one of the Five Fingers, this Syndicate is notorious for their fatalistic and dogmatic beliefs, centered around following mysterious, seemingly random tasks delivered to them known as the Prescripts. Index members dress in flowing white cloaks and uniform black clothing. They are split into the following ranks: Proselytes, initiate members who've been ordered to join the Index by the Prescripts; Proxies, who carry out the will of the Prescripts and punish those who disobey them. A Proxy typically leads a 'familia' of five to six Proselytes; Messengers are tasked with delivering Prescripts to fellow Index members, as wel as civilians within the Index's territory; Weavers watch over massive underground vaults beneath the City, where numerous weaving machines, revered as a God of the City, produce Prescripts through an inscrutable process. Prescripts often range from nonsensical to violent to downright suicidal orders; however, every fulfilled Prescript tends to benefit The Index in some way, even if it is sometimes rather roundabout.

THE MIDDLE — one of the Five Fingers, this Syndicate functions as a massive "family", and an attack or insult against one member is seen as an affront to The Middle as a whole, leading to the offender and all associated with them suffering a disproportionate retribution. Members of the Middle wear purple furred coats, and are otherwise mostly bare-chested, exposing their power-augmenting tattoos. They are split into the following ranks: Little Brothers & Sisters are the rank-and-file; they are watched over by Big Brothers & Sisters; who in turn answer to Greater Sisters. Big Siblings are each provided a copy of the Book of Vengeance, a legal tome that details the exact punishments someone must suffer depending on the offense dealt to a member of The Middle. The offender's name must be written down in the Book before the punishment is carried out.

THE RING — one of the Five Fingers, this Syndicate functions as a twisted collective of artists. They value self-expression but pursue gruesome forms of art dedicated to depicting human suffering by perpetuating it. Residents of areas under control of the Ring are required to regularly attend "tests" held by the Syndicate, and display sufficient artistic aptitude and taste to ensure continued protection from said Syndicate. To be precise, residents are required to relatively consistently get "passing grades" for their art to ensure continued survival under the Ring. One failing grade results in a warning from the Ring, two consecutive fails results in withdrawal of the Ring's protection, and three fails results in immediate execution. Lower-ranking members of the Ring also needs to regularly complete "assignments" issued by higher-ranking members (usually Maestros) within designated time periods (called "deadlines") to ensure continued membership. Members of the Ring wear avant-garde white suits, with their rank within the Syndcate being denoted by the number of coiling rings they wear on their ring finger: Students are the rank-and-file, and wear one coil; Docents are in charge of grading "tests" issued to civilians and Students, and wear two coils; Maestros are leaders of art schools within the Ring, and wear three coils.

THE PINKY — one of the Five Fingers, this Syndicate is the most secretive. Its members often have cover identities that they stick to, no matter what, and will not reveal their allegiance to the Pinky even in the face of death. Some members even hold high ranks within other Fingers. If two Pinky agents end up on opposing sides of a conflict, they are fully expected to come to blows and even kill one another, as to not "break character". Due to their secrecy, very little is known about the Pinky's structure.