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Mamiya Yorun is one of the Demon Lord Knights of the Invidia Archive. She was originally a human until going into a summoning ritual by a mysterious mage, who had given her the power equal to the Trinity Seven. She was given the goal along with three other Demon Lord Knights to bring back "Demise" to this world, as well as to eliminate Anastasia-L, the traitorous saint. Though it backfired as she became friends with both Anna and Lilith Asami. She is currently one of the teachers of the reincarnated Arata Kasuga.


Yorun is smart and a cunning person. She is noted that she is a modest person as well. She also cares and loves her Demon Lord Knights, as she would go as far as to put her own life in danger to protect them, as seen when she took a deadly slash from Ana to protect Inori from being slashed. Informing Inori that she was the same as her, lonely and not being recognized by anyone, until she met Patricia and Chris. Yorun also can be very emotional and be saddened if there were conflict between her friends. As she express concern and tries her best not to worry others, but even so Lilith noticed something is worrying her which she only said that Pandora has a grudge against Ana. She takes pride in her ninja abilities, but due to her kind and soft nature she tend to lower her guard often, nevertheless she would still protect her friends such as Yorun was the only one out of the Demon Lord Knights, to protect Ana from the hostile Pandora. Among the four Demon Lord Knights, she was the only one who did not accept Pandora's enslavement ability, but she could not resist her opponent who wielded power close to the heyday as a Demon King, and was once treated as a source of power. Nevertheless she is cooperative and smart in battle. As seen when outsmarting the demonized Ana by numbers. Yorun tends to be careless, such as mistaken Altana (the mastermind of Ana's demonization) as a beautiful angel because of her looks. She can be serious and strict in battle though rarely.

Yorun has never shown signs of anger, even when she was under the influence of the Demon Knight armor. She maintains a cool and calm attitude. However she can't stand seen naked, such as in Arata's presence, and would become violent.


Yorun is a young woman with slender build, with short black hair, with bangs mostly covering her left side of her face, and her eyes, which is very similar to Levi Kazama.

Yorun main attire is usually her school uniform which consists of a white collared dress shirt worn with a dark blazer jacket which she keeps it open, and a plaid mini-skirt. She also sports a plaid cravat bowtie, black knee-length socks, and loafers. Due to Ana request to all the Demon Lord Knights to stay and guard the school, she never changed her uniform.

In her Demon Lord Knight armor she wears a long white scarf around her neck. A crown-shaped is worn around her head. She wears a thick armor around her abdomen which spreads out to bottom similar to a cape, and a thick spike on the armor, on both shoulders. Both her middle fingers turn black. Her school mini-skirt is kept as it is, Her black knee-length socks, and loafers is transformed into a thick armor.


Yorun is first introduced when Arata suddenly shows up when she and her fellow Demon Lord Knights were bathing. Though remained silent, all the while Altana introduced the Demon Lord Knights to them. She later became one of the teachers to Arata along with the rest of the Demon Lord Knights. She tortures him with throwing multiple kunai at him, which seemingly training him until he notices the presence of an enemy who might be aiming at him. But also she mentions she is torturing due to the fact that he saw her and the other Demon Lord Knight naked as she still haven't forgiven him.

After days of training with Yorun and the other Demon Lord Knights, he is shown to have progress as he managed to dodge the kunai's thrown at him, and later managed to hide his presence completely to the ninja, and even hugging her while asleep which she becomes completely flustered.

After the arrival of one of Aryan underlings whom used Harukage body. Pandora summons the Demon Lord Knights, and the underling immediately tries to kill Arata, but Yorun intervenes to save him, using Shadow Servant to escape. However she was injured which the other Demon Lord Knights are worried about her, but she says that's it's okay, not wanting to worry them. despite it being very painful. Inori tries to heal her. Later the Demon Lord Knights discuss about Arata's current condition. After being told that his training is half done, and as well as defeating the gods by going into advanced training. Yorun and the others that the only way is to master a Demon King Gift ability.

Confusing Arata, Patricia explains the Demon King Gift, then Inori notes that since Arata is already dead has the qualification for a Demon Lord Knight. Yorun remarks that, that the Demon King ability it can reach even the gods. Arata quires if he can beat Aryan if he could master it. Patricia answers that by normal means it is something to only them possess and would manifest over decades and hundreds of years. Depressing Arata. The Demon Lord Knights discuss that it is time awaken Arata's Demon King Gift. Yorun is worried about Pandora, since if she's going to disappear they should respond. Patricia decides to use a technique to awaken the soul of the Demon King. Much to Chris dismay as it is their last resort.

Yorun explains to Arata that only them the Demon Lord Knights whom they have assimilated with the Demon King has a technique. Arata asks the danger it poses, which Patricia answers, that by doing so the the soul of the mage will disappear and the Demon King will take over the body. However Arata Decides to do it nevertheless. Yorun then places her index finger on Arata's mouth, as he is finally betting his life on it, mentioning that Pandora is also betting her life the same way they did. Reminding him that this is a battle to defeat the gods. Arata responds that he just wants everyone to laugh, the Trinity Seven and even Aryan. Seeing his resolve, the four Demon Lord Knight connect to their Archive. They surround him, creating a magic circle and use Four Heavenly Demon technique on Arata.

Having learned the technique has failed along with the rest of the Demon Lord Knights. Arata begs them into meeting Harukage. Yorun finds his determination a nice expression, and tells the rest of them to go with Arata, having believed in him. She and the rest of the Demon Lord Knights later arrive where Harukage is fighting Pandora, who is severely injured. the Demon Lord Knight all then watch in silence as he converse with Harukage. However when Arata asks about her panties since she always wears kimono, everyone is in shock at this comment. When Arata dashes at Harukage, dodging her shadow attacks, Yorun and Chris remember it is thanks to all the training with them. Yorun looks happy at this.


Yorun Thema is Recognize from the Invidia Archive, and her branch magic is Shadow Servant. Her Demon Lord Knight armor is the Demon Lord Knight of Voltea of Blue Dream, which takes over her body and soul, by using this allows her to alter ones self. Yorun tried her best to resist the armor control. By using Shadow Servant or originally known as Cutting Paper, Yorun can alter the appearance of anyone else, it can be used to save companions or create multiple clones of her but changing it's appearance to someone else. She can also use this technique on herself to escape fatal injuries and reappear unharmed. However she will still take damage but is minimized.

Demon's Gift - Being one of the Demon Lord Knights she has her own Demon Gift called Emperor Prison.

  • Emperor Prison - Satan's ability to hold is completely even appearance from the world magic also result in hiding her own magic, an ancient magic cutting technique that changes paper cut into various shapes with magical power, and that she specializes in alter ego.

Yorun is also extremely fast, and can throw multiple kunai's in quick succession. She also possess a sword called Voltea's Great Sword.


  • Yorun is second youngest out of the Demon Lord Knights, Patricia being the oldest
  • Yorun was the only one who tried her best to resist the control of her armor, instead of it taking it over and using it's abilities.
  • Yorun knew the conditions to become a Demon Lord Knights, and the reason she invited Inori to join their group.