|QUIZ TIME! Should you read any further? You might find something out you regret! Spoil at your own risk!|
Yamato Nadeshiko (by Katai Tayama)
2 February (Aquarius) 
Ryunosuke Akutagawa (elder brother)
Battalion Leader of "Black Lizard"
Gin is somewhat short, with pale skin, dark grey eyes, and long black hair. As a mafioso, she keeps her hair in a spiked bun, leaving sections of shoulder-length hair down. Most of it falls to the right side of her face, whilst a strand falls over the middle.
Gin wears a grey, short-sleeved v-neck, black trousers, and black heeled boots. Over her shirt, she wears a long, flared black coat is seen dressed in an outfit comprising of a long black cloak with a hood and frayed trim. The right sleeve, tightened by a black band on her bicep, is long with an extended part with frayed trim, and the left sleeve appears torn off, exposing her arm. She wears reddish-grey gloves that extend a tad beyond her elbows. The right glove being complete whilst the left glove is fingerless.
In addition, she also wears a black choker with a white cross on it, and a white mask that covers her nose and mouth.
Her casual wear is much less elaborate. She leaves her hair completely down, showing it to be silky and a bit wavy, falling past her waist. She wears a light, knee-length dress, black stockings, heels, and a stylish, buttoned coat. She also carries a purse with her. She's noted as being exceptionally beautiful.
As an assassin, Gin is silent and stealthy, described by Michizō Tachihara as being able to sneak behind someone and slash their throats in an instant. This was demonstrated when she snuck behind Ichiyō Higuchi and put a knife to her throat before she could notice. Gin is also loyal to the Mafia and is not below going head to head with someone who goes against orders, as seen when she provoked Tachihara for trying to carry out plans to attack the Armed Detective Agency in his own way.
Fitting of an assassin, Gin is deathly quiet, seldom speaking, and pairs her silence with either indifferent or serious expressions. Her silence is not composure, however. Similar to her brother, she's quick to lash out. Her fellow commander, Tachihara, has no problem antagonising her, ending up as the target of her temper majority of the time. Although she has a sense of humour, it's implied to be rather dry and sarcastic, such as writing "Congrats!" in the dirt to Tachihara when Atsushi Nakajima forces him to hold a baby during the Q Incident.
Hidden beneath her stoic personality, she blushes easily when embarrassed such as when Osamu Dazai mentioned how she was a "dainty little girl" when she was younger and when Higuchi saw her in her civilian clothes. She is also noted to have a very cute voice. When it comes to others, it appears she prefers keeping this side of her to herself, and dislikes being put on the spot over it.
She is closest with Akutagawa, smiling fondly at him and returning home with him after her return from a mission. After Akutagawa promises to Atsushi Nakajima not to kill anyone for half a year, Gin notices Akutagawa's increasing irritability, attempting to find ways to pacify him, but knowing his demeanour leaves much to be desired in terms of relaxation.
Gin has no ability, but makes up for it by having incredible physical skill. She is agile and poised, capable of sneaking behind her targets undetected, making her a valuable assassin in the Port Mafia.
Compared to her older brother, she is more physically fit and capable of handling long-term strenuous activity.
She and her brother Ryunosuke Akutagawa were orphans and used to live in the slums along with about eight other kids. The other children happened to overhear a conversation regarding the time and location of a shipment the Port Mafia were supposed to deliver to subordinates. The men knew about this and sought out the children, beating everyone but Gin and Ryunosuke, who managed to escape thanks to Gin's quick-thinking, to death. After Osamu Dazai extends an invitation to the Port Mafia to Akutagawa, Gin joins as well, however, the full circumstances behind her decision remain unknown.
With Black Lizard united, Higuchi gives them the order to kill the Armed Detective Agency. The squadron easily enters the building the Agency's located in, attempting a surprise attack as part of the Port Mafia's effort on chasing down Atsushi Nakajima, to hand over to the Guild in exchange for a massive reward. However, Black Lizard is overpowered, and Gin is defeated by Kenji Miyazawa.
She later makes her move alongside Black Lizard confronting Ichiyō Higuchi after Ryunosuke Akutagawa's defeat by Atsushi Nakajima. She sneaks behind Higuchi, demonstrating she could easily slit Higuchi's throat if she had to. Despite Akutagawa's grave injuries, Gin and the others question Higuchi's judgement, trying to act without receiving orders. However, despite her cold front, she arrives to assist Higuchi in saving Akutagawa from a rival group attempting to get revenge against the Port Mafia. Given her participation, Gin shows her respect for Higuchi's drive. During Akutagawa and Higuchi's reunion, Gin stands outside the room, seeming to nod in approval.
During the three-way war between the Port Mafia, the Armed Detective Company and The Guild, Gin attempts to monitor Dazai and Atsushi's movements, following Dazai when he starts walking away. Dazai's noticed her the entire time and asks her to reveal herself. Shocked Dazai noticed her, Gin instinctively lashes out, drawing her knife to Dazai's neck. She demonstrates an understanding of Dazai's reputation when calmly putting her away at his request, staying out of his and Higuchi's meeting over the released Yumeno Kyusaku, acting as "guards" to Dazai.
It isn't until Dazai brings up how she used to be much shorter and cuter when first in the mafia, revealing she's a girl. His comment catches Gin off guard, and she looks away, asking him not to change the subject.
After Yumeno Kyusaku's kidnapping by the Guild, Black Lizard participates in defending their territory from further damage of Dogra Magra's widespread mania.
Later, during Ōgai Mori and Yukichi Fukuzawa's secret meeting, she—along with the other Black Lizard leaders—act as the boss's escort detail. The group did not hesitate to try attacking Fukuzawa when tensions overflowed, only to be deceived by Jun'ichirō Tanizaki's Light Snow ability.
The Guild Aftermath
After a long-term absence during of the three-way conflict, Gin returns after being absent on a mission during the incident. She is seen by Katai Tayama in her civilian attire, and Katai sees her as a beautiful young woman he falls in love on first sight. The next time she is seen is by Higuchi, who spots her smiling fondly at Akutagawa, mistaking her as Akutagawa's lover.
Pursued by Katai (along with Atsushi Nakajima and Doppo Kunikida) and Higuchi, Gin attempts to run away. However, she is forced to speak to them when they catch up to her. She explains she asked Akutagawa, revealed as her older brother, to take care of her work clothes after they were done in at a laundromat.
Her appearance and relation to Akutagawa shock the group, leaving her further exasperated. When Katai finally tries to develop a relationship with her, Gin promptly shuts him down.
With the arrival of the "masked assassin", Black Lizard gets assigned to scoping out and raiding his hideout. However, their target already fled the scene. This failure leads to Fyodor Dostoyevsky's "cannibalism" scheme. Assigned to "siege duty" during the raid on the Agency, Gin and the rest of the mafia's most prominent mafiosi move in to kill Fukuzawa to save Mori's life. The group nearly ends in a massive face-off against the Agency, only to be deceived by Tanizaki's Light Snow once more. Black Lizard apprehend him and hold him hostage.
Gin stands behind Tanizaki, with Hirotsu warning Tanizaki that if he doesn't cooperate with the interrogation, Gin will kill Naomi Tanizaki. Naturally, this enrages Tanizaki. His violent mood swing unsettles Gin. The situation escalates, and Tanizaki escapes just as Tachihara tries to shoot him. Light Snow nearly gets Gin killed, until Hirotsu warns Tachihara he might shoot an ally.
Gin hears the door lock, barely evading Tanizaki trying to kill her from behind. Hirotsu comes to Gin's aid, but Tanizaki escapes.
After Alexander Pushkin's defeat and Mori's recovery, Gin accompanies the combined forces of the Agency and Port Mafia to confront him.
With Black Lizard assigned to the Agency's protection after they are framed for several accounts of murder, Gin holds her peace on the subject, leaving Hirotsu and Tachihara to argue over whether or not it's worth the trouble of protecting them when Yosano and the others leave a hidden base against Mori's instructions. She watches in shock as Kenji Miyazawa takes the bait of a car that explodes, mistaking it for Atsushi's.
Government agents attack the group, with Black Lizard protecting Tanizaki and Yosano whilst they help Kenji. The assault leads to the appearance of a mysterious, hooded figure with the ability to manipulate metal. With the drastic turn, Black Lizard and the others make a retreat. Gin remains silent throughout the whole discussion.
The figure tracks Yosano down, revealing the dog tag of the soldier she befriended. In her shock, she's nearly killed, but Gin comes to her rescue, sustaining a gash on her arm. Tachihara later comes to her aid.
After their escape, Gin keeps a hand on her injury, assuring Yosano that the door, rigged with explosives, will keep them safe. Doubtful, Yosano tells them to escape on the boat without her.
She listens in on Tachihara's conversation with Yosano, suddenly walking towards him. She only speaks his name before stabbing him in the stomach. She shouts that her blade is moving on its own, forcing her to stab Tachihara and try attacking Yosano. When she fails, she's forced to stab herself, collapsing while the knife floats away.
- Gin's name references Ryunosuke Akutagawa's work Ogin. The cross on her choker, while most likely aesthetic, could be interpreted as an allusion to the Christian themes found in Ogin.
- The anime simplified Gin's design. Her heels are instead boots, and the cross completely omitted.
- Harukawa often illustrates Gin with completely black eyes, harkening to Gin's hardened soul and her ruthless demeanour as a mafioso. However, her eyes soften somewhat when not at work.