Doma/Relationships

Muzan Kibutsuji
Doma met Muzan and became a demon at the age of twenty. He steadily developed his powers over centuries and eventually became Muzan's second most powerful subordinate and held the position of Upper Two of the Twelve Kizuki. Doma seemingly adored Muzan and would continually talk to him as if Muzan were his friend. During the meeting of the Upper Ranks, Doma excited offered to gouge his eyeballs as response to Muzan's rant over his continual disappointment in their failure. Doma's lack of fear and inability to show true emotion infuriated him, who desired to be feared and respected, and Muzan never liked Doma as a result.

Upper Ranks
Doma acted friendly towards his fellow Upper Ranks. It was his personal belief that superior beings should treat their subordinates fairly and as Upper Two, he was respectful of the demons lower ranked that him. During the meeting in the Infinity Castle, he chatted with Gyokko while waiting for Muzan's arrival, complimenting the pot he was given in his cult room. Notably, he respected Kokushibo's authority as the one demon more powerful than himself; as such, he gently tried to calm him down when he angrily reprimanded Akaza for attacking him, claiming that is their method of getting along. When told he was reinforcing the hierarchy of the Upper Ranks, Doma doesn't deny his words but also responds that they should treat them more justly as the two strongest demons.

Akaza
Because of his desire to become stronger and Doma's strength allowing him to surpass himself to become Upper Two, Akaza harboured an intense hatred of Doma. Doma, as apathetic as he is, considered him his "best friend", seemingly ignoring the contempt Akaza possessed. His carefree and bubbly personality is in stark contrast to Akaza's headstrong and aggresive nature. Moreover, Doma would continually ask his subordinate to eat women, like himself, as they have more nutritional value to demons than men; Akaza vehemently refused to do so and Doma believes this was why he surpassed him in power. During the Upper Ranks Meeting, Doma approaches Akaza and nonchalantly asks if he was worried about him, claiming that he was worried about everyone since they were comrades. Instead of returning his words, Akaza commands him to remove his arm off his shoulder, before destroying part of Doma's jaw when he doesn't do so immediately.Doma doesn't dodge the blow but rapidly heals the damage, before asking if Akaza had gotten stronger.Akaza's hatred for Doma can also be seen when he loses his patience and destroys Doma's head, after he attempts to join Gyokko's mission without Muzan's orders. After Kokushibo admonishes Akaza for attacking him, Doma tries to placate his superior and claims that it is simply their way of showing "friendship". Despite this, he snarkily insults Akaza by claiming he would never defeat him in battle, despite become a demon more recently than him.

Later on during the battle within the Infinity Castle, Doma begins to tear up after hearing word of Akaza's passing, mourning his "best friend." However, Kanao is able to expose him saying that he does not feel any emotion and is simply acting, proving that Doma did not actually care for Akaza.

Daki & Gyutaro
As revealed by Gyutaro during his final moments, Doma was the one who had initiated their transformations into demons after finding them on the brink of death. After Ume had been burned alive and Gyutaro had been cut by a Samurai, the latter carried her half burned body across the district for help, but upon realizing that people who would offer aid to them did not exist, collapsed from exhaustion from his wounds. Doma, having been wandering around the district to devour the beautiful women in the area, stumbled upon the half dead siblings.

Due to supposedly being a "Nice" guy, he offered to give the siblings his blood and initiate their transformation into demon and challenged them to become strong enough to become an Upper Moon such as himself by impressing their "Patron".

Centuries later, after their deaths, Doma was shown to have "felt" a level of responsibility for them, this is seen where he had offered to mutilate himself as punishment for their deaths to Muzan due to him having been the one to initially introduce them to him and join their ranks as Demons.

Kanae Kocho
Prior to the beginning of the series, Kanae faced off against Doma. The two fought until dawn, forcing Doma to escape before the arrival of the sun. Kanae was left with major injuries and died soon after their battle. Doma himself was stated to have been greatly disappointed in their battle ending that way and he had hoped to eat her. As stated by him, Doma acknowledged Kanae's strength during their fight and commended her for it, when he faced Shinobu years later.

Kotoha Hashibira
Doma met Kotoha when she was roughly 18 years old, on a cold snowy night. She came to him while carrying her baby, and pleaded for him to save them from her abusive husband and mother-in-law. As a result, Doma killed her pursuers, and accepted Kotoha and her baby into his temple.

Doma grew fond of her due to her beauty and singing ability, intending to keep her alive until she died of natural causes. However when she discovered that Doma was a Demon who was killing his followers, she ran from the temple to try to escape. Despite his fondness of her, Doma pursued Kotoha and murdered her in cold blood.

Inosuke Hashibira
After joining Kanao to assist in the fight against Doma, Inosuke becomes eager to defeat him so he can become a Hashira, leaving Doma intrigued by the new opponent. However once he discovers that Doma has killed one of his comrades, Inosuke becomes enraged and immediately rushes in to attack him.

Despite being immediately attacked by Inosuke, Doma becomes curious about him and manages to remove Inosuke's mask, mentioning that he recognizes his face. Although Inosuke refuses to acknowledge that he has met him before, Doma explores his memories and reveals that he met Inosuke when he was a child, and was responsible for killing his mother, causing Inosuke to fill with hatred and engage in combat with the Demon.

Shinobu Kocho
Prior to their meeting, Shinobu harbored an intense hatred for Doma since he was responsible for killing her sister. Upon confronting him within the Infinity Castle, Shinobu becomes disgusted by his calm, bubbly demeanor claiming that he makes her feel sick and angrily tells him that her sister was killed by him.

Doma adds insult to injury be recalling how displeased he was at not being able to eat Kanae, which causes Shinobu to stab him intensely through the eye, initiating a fight. Despite her animosity for him, however, Doma would slowly develop an admiration for Shinobu as she struggles fighting despite her small stature and inability to poison him fatally. As Shinobu lives through her final moments, she becomes frustrated that Doma does not appear to be affected by her attacks, nor her poisons and curses him to "go to hell!" before she is killed.

When they meet again the afterlife, Doma has a casual conversation with Shinobu, admiring her for stealthily poisoning him. Despite her hateful responses towards his comments, Doma comes to an unexpected realization by calling Shinobu cute and claiming that even though he "doesn't have a heart anymore, [he] feels like it's beating" when he looks at her. Although he alludes to having romantic feelings for her, Shinobu stares at him and calls him a "worthless bastard" after he asks her to go to hell with him.

Kanao Tsuyuri
When the two originally meet Kanao is filled with hatred towards Doma for killing her loved ones, reacting with his usual exaggerated personality. However Kanao exposes his lies and makes fun of him for not being able to feel any emotion, which angers him.

The two openly express their disdain with each other with Doma referring to Kanao as "the first time [he's] talked to such an unkind girl", with Kanao expressing her desires to "cut off his head and send him to hell as quickly as possible, initiating a fight between the two.