Owing to a mistake by Ratatoskr, Shido accidentally asks to see her panties, to which Kurumi teasingly decides to comply. However, she is stopped by a frantic Shido. Throughout their conversation, Shido is startled that Kurumi is the aggressive one in trying to seduce him. However, their conversation is cut short by Origami and Tohka, whom both fall out of a closet, from which they were eavesdropping.
After school, Kurumi kills three delinquents that she meets while walking along the streets and is then confronted by Mana Takamiya. Origami, having heard Mana’s report, is surprised to see Kurumi appear the next day at school. Confronted by Origami, Kurumi quickly forces her into a corner by summoning various hands from her shadows. When asked about her intentions, Kurumi reveals that she is after Shido.As Shido is forced to take on a triple date, he uses Fraxinus’s teleporter to constantly shift between Kurumi, Origami, and Tohka. During her date with Shido, Fraxinus’s decision causes them to go into a lingerie store. In an attempt to test how far Kurumi will go, Fraxinus gives the command for Shido to ask her to put on a very revealing piece of underwear. Much to everyone’s surprise, Kurumi complies with the task. After Shido returns, Kurumi reveals she had bought the underwear because of Shido's compliment.
However, the date takes a darker turn after Shido is forced to momentarily leave for another date. After Shido left Kurumi, she finds some boys shooting at a stray cat and convinces them to let her play with them. Ratatoskr loses sight of Kurumi as Origami and Tohka run into each other. After they both proclaimed that they were trying to find Shido for their date, Origami runs off, concerned that Shido could be in danger. Shido returns to look for Kurumi but instead finds blood, body parts, and Kurumi preparing to kill a man. As she holds Shido within her clutches, Mana Takamiya intervenes, wearing her CR-Unit.Mana Takamiya delivers the death blow to Kurumi and explains to Shido that <Nightmare> will always continue to return no matter how many times she kills her. Afterward, he is forced out of her way and avoids Origami and Tohka. Tohka finds out the reason for Shido's behavior and goes to his house in an attempt to cheer him up. After gaining some insight to Kurumi, the next day Shido declares to Kurumi that he'll save her. Hearing this, Kurumi tells him not to force his values onto others, as she hates that kind of wishful thinking. Frowning at Shido's proclamation, Kurumi tells him that he should put his words to the test and meet her at the rooftop of the school after class.
After arriving at the school roof, she lets out a chuckle and wonders if Shido still intends to save her after what she has planned. Summoning her shadow, she encases the school in her <City of Devouring Time>, which she uses to slowly steal the time of those who step within the boundary of her shadow. While Kurumi is threatening the school and the town, Origami and Tohka are engaged in battles with other copies of Kurumi. Shido seemingly manages to convince Kurumi, only for her to be killed by another Kurumi. It is revealed that the hands within Kurumi's shadow are actually the hands of other copies of herself.Mana arrives again and immediately cuts off Kurumi’s arm, which she then quickly regenerates by rewinding time using the fourth bullet <Dalet>. She then proceeds to reveal that Mana has only been killing her clones and that she doesn’t even take her seriously. Freezing Mana in place by using the seventh bullet <Zayin>, Kurumi then easily defeats her with a barrage of bullets. Tohka and Origami show up but are immediately restrained by Kurumi’s copies. As Kurumi takes everyone hostage, she attempts to summon a spacequake to destroy the entire town. However, Kotori appears and annihilates the spacequake with her own, having taken back her Spirit power from Shido temporarily to fight Kurumi.
As Kotori prepares to deal the final blow, Shido immediately stands in front of Kurumi to shield her. Knowing that Kotori is no longer herself, he tries to reason with her to spare Kurumi. After the shot was launched, Kotori suddenly regains consciousness. At the last moment, she changes the direction of the projectile, hence saving Kurumi’s life.After the clash with Origami in the park, Kurumi is seen at a rooftop slowly regaining the amount of “time” she lost during her fight with Kotori. There, a mysterious silhouette appears, asking how it went with Shido. Apparently, this being is the one who told Kurumi about Shido’s existence and his ability to seal spirits. When questioned by the mysterious person about her goals for seeking Shido out, she states that her true purpose/goal is to consume Shido and use him as fuel for the 12th bullet, which will allow her to travel 30 years back in time and kill the First Spirit. She believes that the results of her actions will prevent the birth of future the calamities that humanity calls Spirits. The mysterious person mocks Kurumi for being “surprisingly gentle”, before disappearing into the shadows.
Kurumi briefly appears after Shido makes his escape from Tenguu Square. With Tohka captured by DEM, the Fraxinus crew helpless under Miku's influence, and Miku in pursuit of Shido, Kurumi appears and offers her aid to Shido.
With Yoshino and the Yamai twins busy fighting against the myriads of Kurumi's past selves, Shido is quickly taken to where Miku is by one of the past selves under the acceleration effect of the First Bullet <Aleph>. Kurumi drags Shido and Miku into her shadow so that the two can speak privately. However, the strain of fighting three Spirits and maintaining the space proves to be too much for Kurumi, who resorts to using the Second Bullet <Bet> to slow down time for their escape.Afterward, Kurumi receives information about Tohka’s whereabouts from her other selves. She requests a pat on the head from Shido. Kurumi teases Shido further by adding another condition for helping him: something along the lines of saying "I like Kurumi better than Tohka" in front of the <Princess>. Kurumi tells the flustered Shido that she is only joking and reveals Tohka's location. However, as they arrive at DEM’s footsteps, Mana appears and attacks Kurumi. Seeing her chance to move on her own, Kurumi decides to leave Shido to Mana. Before leaving, she assures Shido that the frontal assault caused by clones will remain.
During the aftermath of the battle, Kurumi remarks that she never found her true target, the Second Spirit; the Spirit captured by DEM and the one who knows the identity of the First Spirit.
After seeing Origami tap into her Inverse form, Kurumi takes the chance to talk to Shido. Kurumi tells him that everything he did will become meaningless once Origami went into her inverse form. She then proceeds to shoot Shido with the Ninth Bullet alongside the Twelfth Bullet, sending him five years in the past to find out the reason for Origami's inversion.
After Shido realizes that he had traveled back in time, he suddenly hears Kurumi's voice in his head. He scans his surroundings to search for Kurumi, but she tells him that she is in a different "time". Kurumi explains that she has sent Shido five years into the past using the Twelfth Bullet, <Yud Bet>, as well as the Ninth Bullet, <Tet>, which allows her to connect –communicate telepathically and share senses– with people in a different time. Shido argues that he needs to return to the present to help Tohka and the others, but Kurumi tells him about how she sent Origami to the past before she returned as an Inverse Spirit. Kurumi says she wants proof that history can be changed. She gets a little sentimental and says she's talked too much. She then urges Shido to hurry and find out what caused Origami to go Inverse.
After watching the events of five years ago unfold, Kurumi concludes that by sending Origami and Shido back in time, she has helped to create the current timeline. She concludes that the best course of action is to send Shido back in time again to change history. However, in an attempt to save Spirit mana, the action will be done by the Kurumi of five years ago. Kurumi says that five years ago she was near where the fire broke out. Shido asks if she had met him at that time, but Kurumi denies this and says she was just there to see the flame, as another Spirit could have very well caused a disaster on such a scale. Kurumi says she can guarantee that she was around the fire then, but she did not meet Shido. However, if such a meeting occurred, history would be altered.
Past-Kurumi, who is wearing an eye-patch, asks what business Shido has in a place like this, which prompts him to ask her bluntly for help. Eye-patch Kurumi is surprised that Shido knows her name and warns him not to move. He tries to tell her that he was sent here by the Kurumi from five years later. Present-Kurumi tells Shido that they don't have a lot of time and asks him to touch the eye-patch Kurumi. Shido says it's fine if she keeps pointing the gun at him, but he'd like her to hold his hand. Eye-patch Kurumi cautiously complies, and Present-Kurumi quickly explains the situation. After a moment of silence, eye-patch Kurumi agrees to shoot Shido with the Twelfth Bullet. Before Shido disappears, eye-patch Kurumi wishes him good luck, and Shido tells her that he thinks the eye-patch suits her well. Present-Kurumi lets out a choking sound upon hearing this while the other Kurumi thanks Shido for the compliment and bids him farewell until they meet again five years later.
During the second time jump, Kurumi listens in on Shido’s conversation with Phantom. She wonders if Shido knows who Phantom is. Regardless, Phantom refuses to give answers to Shido on the basis that Kurumi is eavesdropping on their conversation.After Origami’s appearance in the new timeline, Kurumi reappears before Shido and reveals that she has also retained memories of the original world, and she knows that Origami has become a Spirit, but she is uncertain as to what event could have caused Origami to become a Spirit in this world. Kurumi changes into her Astral Dress and says that she can, however, use the Tenth Bullet <Yud> on Origami to find answers. Shido asks Kurumi for her help.
However, the instant that Origami sees Kurumi, she automatically assumes her Inverse form. Origami calls out the name of her Demon King, Devil of Salvation <Satan>, and attacks Kurumi and Shido. Kurumi leaps into air and shoots at Origami, but the shot is easily blocked by Origami's "feathers", while the defenseless Kurumi is torn apart by Origami's attacks. Shido screams out Kurumi's name and turns to Origami, only to be surprised by how her "feathers" and Astral Dress have vanished, leaving Origami in her school uniform. Shido tries to make sense of the events before him and is more confused when Origami asks him what she's doing here. Origami asks Shido if she's had a black out again and says she's been losing consciousness since a while ago. She thinks she's probably suffering from anemia and leaves after asking Shido if he has read the note she's given him.
Kurumi shows up again and tells him that it was only a clone created from the Eight Bullet, <Het>, whom Origami had torn apart. She tells him not to worry but says that it will be difficult to use the Tenth Bullet on Origami like this. Shido wonders if he made a mistake, but Kurumi tells him that their current situation is not as bad compared to what took place in the original world. Shido understands what Kurumi is saying, but he can't agree with her because he wants to know what happened to Origami. Kurumi says she's also interested in how altering past events can change the world, but tells Shido that she's not that softhearted and will be taking extra fees for any favors from now on. She bids Shido farewell and disappears into the shadows.
As <Material A> is being prepared to be transported from Neryl Island to DEM’s Japanese headquarters, Kurumi launches a swarm of her clones to retrieve the captured Spirit. However, at that instant, all of her clones are swiftly defeated by the new Adeptus 2.
After Shido’s condition stabilized, Kurumi emerges from the wreckage of the transport aircraft. She uses the tenth bullet <Yud> to recall the memories of the plane before it crashed. She witnesses a scene where the airplane trembled as a pillar of light erupted from the distance. She concludes that the event has something to do with Shido, and is grateful that she can retrieve the Second Spirit without sacrificing a lot of her clones. However, much to her surprise, the Second Spirit already escaped.
Kurumi comes to visit Nia, the Second Spirit, after the latter received a manga sales challenge from Kotori and the others. During their conversation, both parties obtain information about the other. Kurumi through her clones, and Nia through her Angel. Using <Rasiel>, Nia can determine that Kurumi is the reason why the transport plane had no escorts. Kurumi responds that she was merely there to have her questions answered.
While grateful towards Kurumi, Nia responds that she is a pacifist and won't give critical information to someone like Kurumi. Kurumi sarcastically replies that no one will receive misfortune from her inquiry. Then, she asks Nia about the First Spirit, who appeared in the world 30 years ago. She inquires about the reason for its appearance, the exact time and coordinates of its manifestation, its power, and a way to kill it.
The rest of the conversation occurs off-screen. However, the next time Kurumi appears, she is seen talking to one of her clones. She remarks that it would be impossible for her to defeat the First Spirit. However, she feels that all the murders she committed aren't in vain since her Angel can rewind time. Before leaving, she utters her disdain for the three people responsible for the First Spirit's appearance 30 years ago: Isaac Ray Pelham Westcott, Ellen Mira Mathers, and Eliot Baldwin Woodman.
One month after the conflict with Mukuro is resolved, Shido, Tohka, and Origami are shocked to see Kurumi at school. She asks them what is the problem, as homeroom is about to start. Giving a slight laugh, she tells them that she has returned to this school starting today and looks forward to having a great time with them again.
As Shido remains flabbergasted by Kurumi's appearance in the classroom, Kurumi relaxes her expression and jokingly mocks Shido for not having anything else to say to a long-lost classmate who has just returned to class. In response, Origami and Tohka step forward to protect Shido, asking Kurumi her motives for coming here. Kurumi tells them that she harbors no intentions to cause trouble and how heart-rending it is that they don't trust her. Then, behind her cheerful facade, Kurumi lets out a few snickers. She states it would be easy for her to utilizing a more violent method by summoning her Angel and utilize her clones to take the other classmates as hostages. As Shido shouts back her name in protest, Kurumi laughs out that she implores him to trust her word on it. Meanwhile, their conversation begins attracting gossip from their classmates, which Kurumi deliberately feeds into by voicing out loud even more outlandish and false stories about her staying as a servant in Shido's house. As things settle down, Shido retorts that he wants to do more than welcome her, but also still desires to seal her reiryoku. Much to his surprise, Kurumi agrees but also adds that she has a stipulation to add but suddenly stops herself as class begins.
After class is over, Kurumi asks Shido to speak to her at the school rooftop. Upon seeing Shido's arrival, Kurumi greets him with a small theatrical curtsy. Giving a slight introspective glance, Kurumi half-halfheartedly jokes that Shido has grown considerably more mature since their last meeting, which she justifies probably due to the vast amount of carnage he must have seen. Slightly flustered by the response, Shido quickly brings the topic back to Kurumi's condition. However, just as she is about to give her reply, Shido is struck by a sudden dizziness reminiscent of the numerous times he felt when on the verge of death. Meanwhile, Mana, who had intercepted Ellen's attack against Shido, is overwhelmed in numbers after Ellen summons the numerous <Nibelcol> for reinforcements. Just when it seems hopeless, the numerous silhouettes of Kurumi's clones appear behind Mana. One of the clones adds that they are more than willing to help her in this situation, as even they find it distasteful to bully the weak. Mana, having to deal with DEM first, bitterly states that she will be coming after her when she is finished dealing with DEM.
Meanwhile, Shido wakes up after hearing Kurumi call out his name. Beckoning a return back to the topic at hand, she tells him that her aim is still the reiryoku sealed within his body. Now that he has accumulated ten Spirit's worth of energy, she fancies that the time should now be ripe for that goal. Additionally, Kurumi also recalls that Shido's goal is also to seal her reiryoku. Giggling in a seductive manner, Kurumi states that she has no interest in the happy life Shido is offering and cannot be deprived of her reiryoku at any cost. To that end, Kurumi stipulates a challenge between the two of them; whoever makes the other fall in love first will be able allowed to accomplish his or her goal.