10 Most Meaningful Demon Backstories, Ranked

by

‘Demon Slayer: Kimetsu no Yaiba’ doesn’t just show demons fighting – it explores why they became demons. Many were once people who faced hardship, broken homes, and impossible decisions. Understanding their pasts reveals how they gained their abilities and developed their personalities, making their present actions more understandable and the conflicts more impactful. Here are some of the most compelling demon backstories from the series.

Kyogai

Kyogai was once a skilled drummer, but he was shamed and let go when his playing declined. This deeply hurt him, leading him to withdraw and become obsessed with proving himself again. Muzan, sensing his desperation for approval, turned him into a demon. Kyogai then crafted a mansion to give him complete control over the sounds within it. Being demoted among the Twelve Kizuki was another blow, and his rage seemed directly linked to his desire for recognition.

Kaigaku

Kaigaku had a difficult childhood, growing up as an orphan and resorting to theft to survive. He eventually found shelter at a temple and began training as a demon slayer, but he held a strong disdain for those he considered weak, like Zenitsu, and relentlessly pursued power. Facing defeat by a powerful demon, he made a desperate choice: he consumed demon blood to save his own life, sacrificing his humanity. This explains both his limited ability with Thunder Breathing and his intense animosity towards his former comrades.

Tamayo

Tamayo was a woman who was gravely ill and received a blood transfusion from Muzan to survive, but this came with a terrible curse. She managed to regain some control and break away from Muzan, dedicating her life to medical research in an attempt to defeat him. Driven by her own tragic experience, she focused on blood chemistry and poisons, hoping to find a way to weaken the original demon. Through treating patients and studying the unique marks of Demon Slayers, she pioneered a connection between medicine and the ability to resist demons, something very few others understood.

Hantengu

Hantengu spent his life denying his own wrongdoing, always claiming innocence even when proven guilty. When he became a demon, his body broke apart into separate forms, each representing a strong emotion. This splitting reflected his habit of avoiding responsibility, as each form blamed the others for any mistakes. Understanding his past explains why he constantly runs away, gets defensive, and insists he’s done nothing wrong.

Muzan Kibutsuji

Muzan was born with a life-threatening illness and, desperate for a cure, used the Blue Spider Lily when he was near death. He killed the doctor who administered the treatment before fully understanding its effects, later discovering it had turned him into a powerful demon. For centuries, he continued searching for the flower, hoping to overcome his weakness to sunlight, either for himself or others. The fear of death that haunted him as a human continued to drive his experiments and his creation of new demons.

Doma

Doma was born with a captivating appearance that quickly attracted people and formed the basis of a new religion when he was young. Because he couldn’t experience emotions, he saw worship as something to be understood, not a genuine connection. This allowed him to accept Muzan’s offer without hesitation. After becoming a demon, he justified harming his followers by believing it served a greater purpose. His unusual past explains why he could be polite even while being cruel, and why he was so calmly interested in how humans acted.

Rui

Rui was a sickly child who had trouble walking, so Muzan transformed him hoping to give him a stronger body. He later began harming people, and when his parents tried to stop him by ending his life, he killed them before realizing why they were doing it. This devastating event led him to create a fake “family” with harsh rules, trying to recreate the love he’d lost. His past explains why he forced other demons to act as family members like a “Mother” or “Sister” and severely punished anyone who disobeyed his control.

Daki and Gyutaro

Gyutaro and his sister, Ume (later known as Daki), had a difficult childhood in the Entertainment District, facing poverty and mistreatment. When Daki was brutally attacked, Gyutaro sought revenge, and both siblings were left near death. They were saved by Doma, who turned them into demons. This transformation linked their powers, allowing them to fight together seamlessly and even switch control during battle. Their shared struggles and strong sibling bond are the foundation of their unique and coordinated fighting style.

Kokushibo

Originally named Michikatsu Tsugikuni, he trained with his twin brother, Yoriichi, who was a naturally gifted swordsman and the creator of Sun Breathing. Realizing he was limited by age and illness, Michikatsu chose to drink Muzan’s blood to protect his skills and live forever. This led him to develop Moon Breathing and become a powerful warrior, all while remembering his brother’s exceptional talent. His story is about how the desire for power and a long life led him away from his original purpose as a fighter.

Akaza

Akaza once lived as Hakuji, a young man who resorted to stealing to afford medicine for his ailing father, but sadly, he couldn’t save him. He later found guidance under a martial arts teacher and even became engaged to his daughter. Tragedy struck when a rival dojo poisoned them all, leaving Akaza as the only one who survived. Fueled by rage, he single-handedly destroyed the rival school, which caught the attention of Muzan and led to his transformation into a demon. His fighting style and relentless pursuit of strength are deeply rooted in his past failures – the people he couldn’t protect and a promise he was unable to fulfill.

Let us know in the comments which demon backstories you found the most impactful, and tell us why they resonated with you.

Read More

2025-11-11 22:45