Plot[]
Volume II[]
Kurumi and Takashi Hayase volunteered for the elimination mission against Mio Naruse after receiving Yuki Nonaka's report. Kurumi was with Takashi when he slays a stray demon. When asked if it was alright for her to take part in this mission against her childhood friend, Kurumi states her determination to get the job done, even if it means fighting Basara Tojo.
While Yuki was about to approach a cashier to buy some clothes, she was dragged out of the line by Kurumi. Kurumi explains what the new mission decided by the village is to her sister. They both leave the shopping center without telling anybody. During the Hero group's reunion with Basara, she aims a ball of lightning at Basara but Mio attempts to block the attack with her magical barrier although she was overwhelmed by this.
When Basara says her name, Kurumi shouts at him to not refer to her while calling him a traitor. Kurumi angrily shouts her disbelief at Basara for protecting the previous demon lord's daughter after what her sister went through the last five years. When Maria Naruse tries to strike her, Takashi defends the attack. This battle was stopped by the destruction of the barrier that separated the space from the real world.
Shiba Kyouichi scolds Takashi and Kurumi for fighting in a barrier in those conditions and the three Heroes left together after postponing the match until a week after. On the day of the appointed battle, Kurumi arrives with the other Heroes. Whilst there, a duplicate barrier that shifts dimension is formed right in front of her eyes. As soon as the battle starts, Basara charges towards Takashi but slips past him and continues on towards Kurumi and Yuki.
Seeing this, Kurumi begins chanting and as Basara aims for Yuki, Kurumi blasts him with a gust of wind which sends him flying a couple of hundred meters above the ground. She follows him up in the air and overtakes him with an even faster wind. Kurumi uses a prepared magic circle to release a torrent of fierce gusts at point-blank range towards Basara, sending him towards the ground. After he survives, she realizes that he intended to fight her from the start.
Kurumi begins taking things seriously as she flies past rooftops while constantly attacking Basara with the wind. As Basara runs up a wall after merely dodging one of her attacks, she uses gale magic to chase him from behind but shoots compressed air from the top which later creates a three-meter radius crater after Basara dodges it. She hovers towards Basara who landed on the opposite building but he suddenly jumps towards her by using Brynhildr as a stepping stone and strikes her in her stomach by rematerializing the blade.
Although Kurumi was surprised by this, she managed to form a magical barrier in the nick of time which repelled Brynhildr. Using this situation, Kurumi blows Basara with a torrent of turbulent air, crashing him into a nearby office building. As Basara continues to fly through obstacles, he is finally stopped by a huge, steel locker. After a brief discussion with Basara, Kurumi begins focusing her wind around her right hand, compressing a mass of air to the limit which had a diameter of 1 meter.
She released the air towards his stomach but it dissipated. Kurumi is dumbfounded by this and remembers Basara's old ability, Banishing Shift. As she tries to summon a barrier to defend against Basara's strike, it doesn't appear. She realizes Banishing Shift was used on both her wind magic and her channel to her spirit but it was already too late.
Basara saving Kurumi
Basara's slash sends her flying into the air and as she falls down from the building, Basara saves her by grabbing her and landing, absorbing the shock of the fall on his knees. Safe on the ground, she tells him to let her go and as he does so, it reveals her bare skin on her right side of her outfit which was torn from the attack.
She hastily tries to cover herself but pain shoots through her which was due to a broken rib or two. She loses her animosity towards Basara and remembers the compassion he once felt for her. She notices her sister approaching them and tries to warn Basara to block her attack, but he couldn't respond in time.
With the knocked out Basara, Yuki tells her younger sister to look after him as she continues on to resolve the situation. During her alone time with an unconscious Basara, she then takes a good look at him since it's been five years since she last saw him, and then notices how much he's grown and how manly he looks.
After a moment of silence, Kurumi then notices that Basara is talking in his sleep apologizing to her, Takashi and Yuki blaming himself for what happened five years ago. She then realized that he was also suffering from that day if not even more than her and her comrades. After Shiba resolves the situation, the heroes return to the village to report on the situation to the village.
Volume IV[]
After reporting back to the village, Kurumi is assigned as additional support to her sister Yuki and arrives in time for her save Basara from a hoard of brainwashed people in a subway station. After arriving back in the Toujo residence Kurumi and Basara walk in on Mio and Yuki's latest exercise in submission, in which they have become dogs to submit to Basara.
After Mio runs off in sheer embarrassment Maria, Basara, and Yuki properly explain themselves Kurumi makes the mistake of bragging about her superior sexual prowess. Ultimately, the younger hero ends up being cursed with a Succubus curse by Maria and she has to be subdued by Basara. She also aids the other members of the Toujo residence in trying to find out who is responsible for attacking Basara.
Ultimately ends up the unwilling hostage of Ornis when he attempts to kill Basara, only for both of them to be saved by Chisato Hasegawa. Later that night, Kurumi ends up being roped into another game of submission by Maria wearing the same dog costume her sister had earlier on however they are interrupted by the appearance of Maria's sister Lucia who has come to take them to the Demon Realm.
Volume V[]
The members Toujo residence manage to stall their arrival until Christmas Eve. In the meantime, Kurumi ends up the favorite plaything of Maria who repeatedly curses her through a Succubus curse preparing her for the arrival into the Demon Realm, whose harsh atmosphere is difficult to endure for humans without practice or demonic power. She also utilizes her spirits to simulate romantic interactions with Basra every night.
The night of their arrival in the moderate faction city Wildarts Kurumi follows Basara and Maria into Lucia's room and witnesses Maria's punishment at the hands of the two elder siblings, and Lucia, thoroughly aroused by the act that Maria and Basara had just put on, decides to take her pent up sexual frustrations out on Kurumi, but ultimately settles for simply cursing her and watching Basara subdue her.
As thanks for entertaining her Lucia gives Kurumi a Demonic Spirit, similar to her elemental spirits, but easier for her to control in the Demon Realm, and with the added benefit of shielding her from the environment's harsh atmosphere. Unexpectedly the spirit proves to come in handy when the city comes under attack by three Heroic Spirit's and the demons Balflear and Nebra.
Kurumi and Yuki team up to defeat one of the spirits, the plan being for Yuki to distract the spirit followed by Kurumi hitting it with an attack from her Demonic spirit. Unfortunately Kurumi ends up using the charge for the spirit saving Yuki from one of the Heroic Spirit's blows, but fortunately, Yuki is able to dispatch the creature none the less.
Volume VI[]
In the third of Volume 6's side stories, Kurumi works to attempt to master the newly Acquired demonic spirit, without much success and ends up picnicking with Maria instead. That night, Lucia gets up in arms about Shella and Maria stealing something from her closet but gets sidetracked by Kurumi, using magic to strip her of her clothing in preparation to molest her.
According to the family of Succubi, Kurumi has a certain innocence about her, that riles the succubus instinct to thoroughly corrupt her and make her sink into the depths of depravity, hence why they've been harassing her. After Lucia is distracted by another matter Shella scoops Kurumi up and takes her back to her room and gives her a Baby Doll Negligee to replace her ruined clothes.
Kurumi is made to confess that she wishes she could have the same type of relationship Basara has with the other girls, but there is a slight problem with her getting the Master-Servant Contract. Unlike Yuki's posting which is permanent, Kurumi could be called back to the village at any time, where an examination would expose the Master-Servant contract.
If the village realizes that Basara and Mio, whom they already feared because of their immense power, have been increasing their powers by making Master-Servant contracts then a kill order would not only be placed on them but also Zest, Yuki and herself without hesitation. It is at this time that Kurumi realizes that the negligee has a powerful succubus curse placed on it and the only cure for it is to get Basara to relieve her.
Kurumi walks into Basara's room as he's already in the middle of sub-doing Zest and explains the situation to them, including her pent up feelings and sexual frustration. Zest gets the idea to create a pseudo-master-servant contract with Kurumi by leaving a hickey on her throat, with Kurumi being subdued and sexually submitting.
Later that morning Kurumi learns that her Demonic spirit has recharged it's power and is now obeying her properly. It's explained that as the former spirit of a powerful succubus the spirit is used to deriving power from sexual interactions, combined with Kurumi acknowledging and accepting her 'dark side' (her unrequited feelings for Basara) her affinity for the spirit has gone way up. She also realizes that this means that it's necessary for her to continue to have relations with Basara in order for the spirit to continue to function properl