Kōyō Ozaki/Relationships

Kōyō and Mori have a harmonious professional relationship as fellow higher-ups in the Port Mafia. For instance, they once spent time with each other amidst the falling cherry blossom petals. While Mori perceives Kōyō an indispensable, strong, and proficient individual, Kōyō teasingly views Mori as an "unreliable boss" whom she must help in stitching back the Mafia in order. Nonetheless, she professes her loyalty to him as the current Mafia boss quite different from his predecessor whom she held a grudge on, and she trusts Mori's judgment as Mafia boss ever since Osamu Dazai's and Chūya Nakahara's entrance in the Mafia.

Though Kōyō opts to speak to Mori blatantly at times, for example once dryly threatening to "sew his mouth shut", she retains a formal rapport with him and appears to hold respect for him behind his back. In addition, during Mori's virus affliction, Kōyō personally guarded his chamber and almost killed Jun'ichirō Tanizaki, despite not wanting to cut down one of Kyōka Izumi's colleagues, for the sake of protecting Mori.

### Chūya Nakahara

Kōyō was tasked to oversee Chūya upon his entrance in the Mafia. As Chūya usually called her "**big sis**" (姐さん,, *ane-san*, *lit.* "elder sister"), Kōyō didn't prefer it initially, though she would later accept it over time. Kōyō once brought the newcomer Chūya to a meeting for him to gain experience, advising him how their guest was important to the Mafia albeit expendable should they display hints of aggression to anyone like Chūya. Furthermore, Kōyō voiced out her concern to Mori about having Chūya and Dazai work together in the Mafia after seeing their mutual disapproval towards each other, to which Mori ambiguously responded as a seeming test to figure out whether "only a diamond can polish another diamond".

Eventually, as Chūya rose in the ranks as Mafia executive like Kōyō, they appear to have mutual respect and professionalism towards each other, occasionally seen working together personally. For instance, Kōyō and Chūya were both informed of the Cannibalism virus that plagued both Mori and Armed Detective Agency president Yukichi Fukuzawa, making them deliberate on the optimal solution. While Chūya immediately displayed willingness to crush the Agency, Kōyō showed reluctance in playing right into the enemy's hands, albeit ultimately having no choice but to wage war on the Agency.

### Ace

Kōyō shows distrust towards Ace, which the latter also displayed. She dryly ridiculed how Ace was the first to take shelter during the Guild war, to which Ace fired back that she was the first executive to get captured, much to Kōyō's contempt. She thus warned Mori about Ace's absence of loyalty to the Mafia and tendency of treating the Mafia as bodyguards, visibly showing her disapproval and voicing out her wariness to Mori's decision in handling Fyodor upon his capture.

### *Port Mafia's Previous Boss*

When she was young, Kōyō admired a man and attempted to escape with him away from the Mafia. However, the erstwhile boss—Mori's predecessor—discovered this and had the man killed. Since then, Kōyō harbored a grudge towards the boss. Mori's succession as Mafia leader then compelled Kōyō to change her perspective to the Mafia, claiming that she prefers the present organization and would do anything to prevent it from reverting to its former nature that she detests.

## Armed Detective Agency

### Kyōka Izumi

Kōyō is very protective of Kyōka, having taken a liking to her due to their similar abilities and seems to see her past self in her, acting as a maternal figure to Kyōka. Initially, she fights to bring Kyōka back to the Mafia, as she strongly believes due to her past that killers like herself and Kyōka can only ever live in darkness. As such, Kōyō is well-aware of Kyōka's natural instincts of harming or killing other people on account of self-preservation, once asserting during their encounter how Kyōka instantly engaged in combat rather than first resorting to negotiation or even coercion and likening her to a demon.

However, Kōyō apparently wishes to genuinely give Kyōka the chance to live a life in the light that she herself never had. Hence, she is later willing to make a deal with Dazai to ensure Kyōka's safety and even asked Atsushi Nakajima, a previous opponent and now the girl's colleague, to look after Kyōka, showing that she cares very much for Kyōka.

### Atsushi Nakajima

Kōyō initially viewed Atsushi and the Agency as the ones who fed Kyōka lies into making her believe she can live in a world of light, claiming that they would only eventually use her Demon Snow for their gain. Kyōka, however, retained hopeful and trustful of the Agency, making Kōyō deem her to be blinded by the light Atsushi showed. She then threatened to kill Atsushi, during which Kyōka stopped her and feigned coming with her in an attempt to mislead her.

In her captivity in the Agency, Kōyō still showered some insults and showed animosity, albeit more restrained, towards Atsushi. Eventually, with Dazai's interference to negotiate with Kōyō for Kyōka's sake, Kōyō opened up to Atsushi and warned him that Kyōka would kill many people in the three-way conflict if unthwarted; she then entrusts Kyōka to Atsushi, placing her faith in him.

### Osamu Dazai

During Dazai's time in the Mafia, Kōyō and her torture squad would be occasionally aided by Dazai in interrogating "iron-willed victims", all of which ended up divulging information. Later on, Kōyō deems Dazai a traitor for deserting the Mafia and adds that a lot of mafiosi, including herself, wanted him dead.

However, she became willing to make a deal with him in exchange for helping Kyōka, later asserting that Dazai is "a terrifying man" for having predicted the outcome of the three-way conflict and Kyōka's involvement in its conclusion. Moreover, Kōyō also believes that "Dazai's locks are not seen by the naked eye", indicating that he persuades people even like herself through his manipulation and words.

## Others

### *Kōyō's Lover*

In her youth, Kōyō tried to leave the Mafia with an older man she dearly loved. The man apparently promised Kōyō that he would show her "the brilliance of the outside world", which she professes was once her desire, and that they would overcome anything once they lived together. However, the then Mafia boss found out about their plan and had the man killed, much to Kōyō's grudge towards the boss. His death then influenced Kōyō's belief that those who had been bred in the darkness cannot live in the light, lest the light end up burning them, similar to what happened to her.