Ryūnosuke Akutagawa/Relationships

Gin Akutagawa
Gin is Akutagawa's younger sister and only remaining relative. The two siblings grew up in the slums together along with eight other children and are the only survivors of the massacre that got the eight other children killed. Although not much is known about their sibling relationship, the two seem to be on good terms with one another shown by Akutagawa picking her up at the laundromat after Gin had been away on a long-term mission and Gin trying to figure out ways to calm and refresh his spirits. Though Akutagawa is supposedly familiar with Gin the most, at times he finds some of her casual behaviors puzzling such as when she stops in the middle of a walkway to pet a cat.

Ichiyō Higuchi
Higuchi is a mafioso of the Port Mafia who works under Akutagawa and acts as his assistant and bodyguard. She is shown to be very loyal to Akutagawa and is always willing to fight alongside him.

Osamu Dazai
Akutagawa is Dazai's former subordinate. At the age of 14, a young Akutagawa had met Dazai, who would soon become his mentor. As his subordinate, Akutagawa had underwent horrific and abusive training that would shape him into the feared man he is. Only enduring Dazai's berarting, he greatly yearns for his validation, often going to extreme lengths to hear a few words. Even after Dazai leaves the Mafia, Akutagawa strives for his approval.

Atsushi Nakajima
Akutagawa and Atsushi met one another only by accident, when Higuchi had led them into an alleyway and trapped the two. Akutagawa, originally seeing Atsushi as another weak person, was on a mission to collect Atsushi for a bounty. Akutagawa eventually comes to learn the Atsushi is Dazai's new subordinate, and greatly resents him. While Dazai boasts about Atsushi as his new subordinate, Akutagawa begins to feel an even stronger hatred for Atsushi and obtains a will to kill him in hopes that he will earn Dazai's approval. Despite these conflicts, the two will work together ever so often, though often begrudgingly.