Gin is a female character with long, black hair, typically secured in a spiked bun during Port Mafia missions, with sections of shoulder-length hair left loose, especially framing the right side of her face. She consistently wears a white mask covering her nose and mouth. Her signature outfit features a gray short-sleeved v-neck shirt, black trousers, heels, and a distinctive long, flared black coat with a frayed trim; the coat boasts an extended right sleeve cinched by a black band on her bicep and a torn-off left sleeve revealing her arm. Accessories include reddish-grey gloves stretching beyond her elbows – fully covered on the right, fingerless on the left – and a black choker bearing a white cross (omitted in anime). In civilian life, she wears her silky, wavy hair completely down, past her waist, adopting a more feminine style with a light knee-length dress, a stylish buttoned coat, stockings, heels, and a purse. A later vampiric transformation alters her appearance. Her personality is defined by near-total silence and emotional reserve, rarely speaking and maintaining a stoic or indifferent expression. She possesses exceptional stealth, described as having eyes that "absorb sound" and moving so silently it seems she was "painted into reality," enabling her to approach and eliminate targets undetected. Despite her calm exterior, she reacts with swift anger when provoked, often directed at comrade Tachihara, though her irritation is usually brief. A dry, sarcastic sense of humor occasionally surfaces, like writing "Congrats!" in dirt to mock Tachihara. She blushes easily when embarrassed, such as when noticed in civilian attire or when childhood traits are mentioned, and actively conceals this vulnerability. Over time, she shows increased willingness to interact with coworkers and demonstrates concern for their well-being. Gin lacks supernatural abilities but compensates with exceptional physical skills. Her natural aptitude for stealth allowed her to evade attackers during a slum massacre and makes her a highly effective assassin. She is ambidextrous, writing with her left hand but wielding blades proficiently with either. Her agility and poise facilitate rapid, silent movements. She exhibits greater physical endurance than her brother. She and her brother Akutagawa were orphans raised alongside roughly eight other children in the slums. After the other children overheard Port Mafia shipment details, gunmen executed them. Gin's quick thinking enabled their escape. She tended to Akutagawa's injuries afterward and expressed reservations about his pursuit of vengeance, which he ignored. She joined the Port Mafia when Osamu Dazai recruited Akutagawa; her specific motivations remain undisclosed. Paul Verlaine personally trained her early on, accelerating her rise. Despite lacking an ability, she attained command of a Black Lizard battalion. During the conflict against The Five Deadly Omens, Gin participated in negotiations with Fitzgerald while simultaneously aiding Tachihara in protecting Akiko Yosano from Hunting Dog member Saigiku Jōno. Jōno manipulated her sword, forcing her to stab herself; Tachihara's intervention minimized the injury. Later, she was bitten by the vampirized Ichiyō Higuchi, resulting in her own transformation. She resides with Akutagawa, observing his increased irritability after his vow to abstain from killing for six months and attempting unsuccessfully to pacify him. Her closest bond is with Akutagawa, smiling fondly at him and returning home with him after missions. She collaborates professionally with Black Lizard members like Tachihara. Author Harukawa uses completely blackened eyes to symbolize her hardened mafioso persona, contrasting with softer depictions during non-work moments. Her attire intentionally obscures her gender. She reportedly finds cats appealing. Her name "Gin" means "silver," referencing Ryūnosuke Akutagawa's short story "Ogin," while the cross on her choker may allude to Christian themes in that work. Her surname combines "refuse" (芥) and "river" (川).