Akaza/Relationships

Keizo
Following the death of his father, Hakuji goes on a rampage and begins to fight with a crowd of men. As a result of the commotion, Keizo is called to settle the fight and discovers that Hakuji has knocked all of the men unconscious. He attempts to recruit Hakuji as a student at his dojo after being impressed by his fighting skills, and notices the criminal brandings on his arms. Keizo comes to understand Hakuji's situation and promises Hakuji that he will be reborn as one of his students, showing his genuine concern for his well being. He further provokes Hakuji by challenging him to a fight, but when Hakuji attempts to attack Keizo, he is swiftly knocked out by the dojo instructor.

After defeating and seeing Hakuji's potential, Keizo happily invited him to become a pupil of his dojo and instructed him to become the caretaker of his sickly daughter. For the next couple of years, Hakuji proceeded to diligently train under Keizo's instruction and soon became well loved by his teacher to the point where he offered his daughter to marry Hakuji. Keizo's warm acceptance of Hakuji brings joy to his life and he begins to see Keizo as an inspirational father figure as well as a respected teacher.

However upon learning of Keizo's and Koyuki's murder at the hands of the rival dojo, Hakuji once again falls into a homicidal rage and proceeds to brutally murder 67 members of the dojo. Their death affect him greatly to an extent that he doesn't attempt to fight back when Muzan converts him into a demon, even saying that "I don't care anymore, I don't care about anything." Displaying his realization that he had lost the most important people in his life, yet again.

During his battle against Tanjiro as the Demon Akaza, he gets struck by the swordsman with such a strong impact that he remembers Keizo disciplining him. Then envision of his master causes Akaza to slightly regain his humanity and cease his will to fight. Keizo's spiritual apparition comes forth to remind Akaza once again that "even in death he will not forsake him" but that he must pay for the sins he has committed. Within Akaza's final moments, Keizo still guided him as a son and pupil, eventually reuniting in the afterlife.

Tanjiro Kamado
Upon first meeting Tanjiro, Akaza first attempted to kill him quick and swift before even giving him a chance to defend himself due to deeming him to be "weak" and thus a bother and not worth his attention,causing the demon slayer to instantly dislike him.Later upon Akaza successfully defeating Kyojuro Rengoku and then fleeing the scene due to dawn approaching,Tanjiro began to greatly resent the Demon due to him insulting and looking down on Kyojiro despite him giving his all against his battle against him and later insulted the Demon and threw his blade into his back as he escaped and calling him a coward.

This event seemed to have greatly insulted and hurt Akaza's pride,as seen where he was steaming with anger due to remembering Tanjiro calling him a coward and later rationalized that he wasn't one and he simply made the logical choice as he would have died from the sunlight and the fact that Kyojuro probably could no longer fight back against him, but non the less still felt anger at the demon slayer and causing him to then swear to kill him the next time they meet.

Later upon reuniting in the Dimensional Infinity Fortress,Akaze excitdely attacked and ambushed Tanjiro and Giyuu upon sensing Tanjiro's presence,he then proceeded to fight both him and Giyuu in battle using his Full Power,During the Course of which Akaze had become incredibly delighted to see that Tanjiro had improved vastly in comparison to his skill and power level during their first meeting and constantly praised him on all the "strange" techniques he had learned to use during this time gap,having happily proclaimed that it was a good thing that Kyojuro Rengoku had died back in the train and not Tanjiro,due to Akaze having realized that the Flame Pillar would have not likely gotten anymore powerful even if he did survive,causing him to thus then deem him to be "worthless trash".

This in turn severely enraged Tanjiro due to Akaza's blatant insulting his dead comrade who did his absolute best and poured all of his strength in his duel with the Upper Moon,causing him to then react angrily on Akaza's insults. Akaza in turn was baffled by Tanjiro's reaction as he was trying to complement him and later explained his mentality and philosophy on the weak and the strong and how the weak should just die and that helping the weak was pathetic. This in turn caused Tanjiro to take a more sorrowful expression of pity at the demon,he then explained to him that not a single person was ever born strong from the beginning and that everyone had always started out weak and unable to care from themselves and would thus then needed to have relied on others to help them,Tanjiro then sorrowfully explained that even though Akaza didn't remember it,he had someone to help him too.

This in turn caused a stirring in the Upper Moons memories,causing him to remember phantom visages from his past and caused him to remember important people from his life as a human,causing severe emotional inner turmoil for the Demon,who began seeing this person's form overlapping with Tanjiro. Unable to process his long forgotten emotions,Akaza thus then decreed that Tanjiro was "Unpleasant" and needed to be killed immediately causing him to completely drop whatever friendly facade he had and focus on killing him as soon as possible.