Kalo is a Sottocapo of The Thumb. Kalo is a middle aged man with short white hair and chinstrap beard, with multiple scars on his face and a prosthetic right hand. He wears a black suit and jacket, as well as his red Thumb coat hanging from his shoulders. Kalo carries a cane and a silver pistol. Kalo has a stoic and authoritative attitude. As a member of the Thumb, Kalo reflects its values and follows its rules to the letter, expecting his subordinates to respect hierarchy in every way, and punishing them through bodily mutilation upon their failure to do so. Kalo is shown to be somewhat forgiving for a person in his position within the Finger.

Denis is a Capo of the Thumb. Denis has short, messy, brown hair that covers his right eye. His eyes are green and he has a medium complexion. Denis wears a slightly different outfit than the usual Thumb uniform, a grey coat over a black suit that is wrapped with a black cloth which also covers a black scarf or turtleneck. He also has the standard Thumb coat, red with a golden trim, slung over his shoulders. Denis is one of the more reserved members of the Thumb, but no less loyal. He is well aware of the consequences that come with disrespecting Kalo, and even carries out said punishments. He appears to have a lesser-known maniacal personality shown when he shoots from his rifle, expressing bloodlust.

Boris is a Capo of the Thumb. Boris has short combed black hair and displays an average physique. Along with the usual Thumb attire followed by a black suit and red coat, he wears sunglasses, smokes a cigarette and has a ring on his right index and left middle fingers. When in combat, Boris wears steel knuckles. Boris has a tough and straightforward attitude. He's very confident in his physical strength, preferring engage with his fists as he's the only member of The Thumb to not utilize guns, instead relying on his steel knuckles to do the job. He greatly values the Thumb's members and their rules, often enforcing them with a harmful display of physical strength.

Katriel is an Capo of the Thumb. Katriel is a tan-skinned woman, having a more attractive and curvy build with exaggeration. She has long, wavy, purple hair with choppy bangs. She has amber eyes and round, wireframe glasses. She wears the standard Thumb uniform, being a dark grey suit under a gold-lined red overcoat draped over her shoulders, a gold badge on the left lapel, and black shoes. She also wears a belt of grenades, a double-barreled rifle with a bayonet attached. She's notable based on her appearance and cleavage, but also loyal like the other Capos. She's also quick to realize anything of her mistake and willingly to take any punishment for it. As for example, she has a missing tongue which she irritated a Star of the city ruling figure. And took full responsibility and had Denis to take her tongue off.

He is a Capo IIII of the Thumb, ranked directly beneath the Sottocapo. Lei Heng is an imposing man of strong build and tall stature, seemingly surpassing two meters. He has a tan complexion and brown eyes. He has slick black hair that reaches his shoulders, parted in the middle and partially tied back in a ponytail, and with a dyed golden strand on the left. Lei Heng sports some stubble, and is seen smoking a cigar. Wearing a red outfit with gold lines, He carries a large dadao that features exhaust pipes for the use of propellants, attached to his hip through an ammunition belt around his waist. As a high ranking member of the Thumb, Lei Heng has a nonchalant demeanor, being used to receiving respect and carrying no regard for those beneath him. He appears confident in his role and comfortable in most situations.

Valencina Bognatelli is a disgraced Sottocapo of the Thumb and the tutor of Lucio. Valencina is a tall, attractive, older woman with sea green eyes and long, bushy dirty-blonde hair that covers her right eye. She wears a Thumb uniform consisting of a rose-red jacket, trousers, wide brimmed hat and untied ribbon over an ivory shirt with the top buttons undone. And has black gloves with light palms. Valencina is an arrogant, booze-loving woman with a violent, foul-mouthed personality. She has an excessively short temper, taking to physical abuse whenever she feels frustrated regardless of if she lacks excuses to justify the behavior. Valencina regards the woman with no shortage of disrespect and contempt, and has no qualms about treating the others around her with the same discourtesy. Despite her untimely discharge, Valencina continues to carry traits typical of the Thumb, demanding respect from those she views as her inferiors and taking to injury as the first response to failure. By striking down, Valencina affirms her perceived status as someone deserving of more than the stagnation of the House of Spiders.

He is an apprentice of the House of Spiders under Valencina whose duty is to become a "Textbook". Lucio is a tall young man, with violet eyes and light gray hair split neatly to reveal his face, tied into a long ponytail that reaches his waist. He wears a Thumb uniform consisting of a vest, trousers, and a buttoned ivory shirt fastened with a dark red tie, with his sleeves rolled up past his forearm. Quiet and steadfast, Lucio carries an air of professionalism unlike his mentor. He is calm.