In Galvanize, Noshiko joined Kira, Ken at a family dinner with Scott McCall, who Ken had invited over, both as a thank-you to Scott for saving Kira from a wild coyote in the high school, as well as an attempt to help Kira make a new friend and potential love interest.
After they all sat down at the table, Noshiko assumed that Scott, as someone who lived in California his entire life, has eaten at some "pretty impressive sushi restaurants" before remarking that her husband Ken, who had made sushi for their dinner, was a superb chef. Ken set the sushi on the table and pointed out the different kinds, and when Scott looked confused, Noshiko correctly guessed that Scott had actually never had sushi before. Kira, embarrassed, exclaimed that she thought they were having lasagna for dinner, but when Scott assured them that it was great, Kira began teaching Scott how to use chopsticks, a romantic gesture that did not go unnoticed by Noshiko.
As the dinner continued, Scott mentioned that he had heard they just moved here from New York, and Noshiko confirmed this before adding that she has several generations of family history in this region. When Scott asked if Yukimura was Japanese, Noshiko and Ken revealed that it was before explaining that while Noshiko is, in fact, Japanese, Ken is Korean, and he took her name to honor her unique heritage. Kira became even more embarrassed when Ken said he wanted to do a brief unit on Noshiko's lineage for class, leading Noshiko to gently scold her for not having pride in her heritage, though this scolding was interrupted by Scott, who had accidentally mistaken his wasabi for guacamole and began coughing from how burned his mouth was.
In Illuminated, Kira was brought to the Beacon County Sheriff's Station in the aftermath of her being kidnapped and nearly killed by William Barrow (who, unbeknownst to everyone, was being manipulated by the Nogitsune through his flies in order to activate Kira's latent Kitsune foxfire powers and jumpstart his possession of Stiles Stilinski). Kira, along with Scott McCall, Lydia Martin, and Stiles Stilinski (who had found where she had been taken through Lydia's Banshee powers in an effort to save her) was questioned by Sheriff Stilinski and FBI Special Agent and Sheriff's department liaison Rafael McCall, Scott's father, about what happened. Afterward, when Kira asked if she could have her phone back (as she was afraid of the photos of her fiery aura being found by police), Rafael insisted it was being taken as evidence before informing her that her mother Noshiko and father Ken would be coming down to sign some paperwork.
In Riddled, Kira was studying in her bedroom late at night when suddenly, her bedside lamp's bulb burnt out. After turning the switch did nothing, Kira called out for Noshiko to ask her if they had any light bulbs before reaching for the bulb to twist it out of the socket. Much to Kira's surprise, sparks of electricity came off of her fingertips and caused the bulb to light up, surprising her so much that she jerked her hand away. Kira then curiously reached out toward the bulb once again, delighted when the bulb once again lit up, though her delight quickly turned to horror when the bulb was overloaded with electricity and exploded into dozens of small shards of glass.
Noshiko, with a new bulb in hand, walked into the room just as the burned out bulb burst. The explosion seemed to upset Noshiko, who snapped that Kira should be asleep before kneeling to clean up the glass shards and unscrewing the remnants of the old bulb. When she put in the new bulb, similar pink sparks of electricity briefly lit up the bulb before Noshiko suppressed it, though it did not escape Kira's notice. Before Kira could ask questions, Noshiko firmly ordered her to go to bed before rushing out of the room, leaving Kira to wonder if her mother is a Kitsune like her.
In Letharia Vulpina, Noshiko was coming out of the hospital after having attempted to find the Nogitsune when she saw Kira use her powers of Super Agility (to protect passerby at hospital from a live wire cut by the Nogitsune-controlled Stiles Stilinski) and Electrokinesis (to siphon the electricity from the wire to ensure no one else was electrocuted by it). Noshiko immediately found Kira and rushed her away from the scene, stating that she had seen what Kira did and admonishing her for using her powers in public.
The next day, Kira was walking down the hallway in the high school when she saw Noshiko and her father, Ken, duck into the latter's classroom. She spied on the two of them from the window, where she saw Ken reveal that he had been keeping the physical representations of Noshiko's Kitsune tails in a hollowed-out book. She listened as Ken pointed out that Noshiko had already sacrificed five of her tails and asked her how many more she was willing to lose, becoming concerned when Noshiko made it clear that she would sacrifice all of them to stop the Nogitsune if it came to it.
Kira then watched as Noshiko removed two more of the tails (which were in the form of black ceramic daggers known as kaiken) and snapped them in half, using the energy within them to summon two more Oni, assuring Ken that these ones would be stronger due to the tails being older and thus more powerful. Knowing that the Oni would soon be going after the Nogitsune (and, by extension, her good friend Stiles Stilinski, Kira rushed away from her parents so that she could inform Scott and Stiles of what she had learned.
In The Fox and the Wolf, Kira (and her boyfriend Scott McCall) were summoned to the high school by Noshiko after Ken was infected with one of the Nogitsune's flies. When the two gave Noshiko a katana and a photograph found by Stiles Stilinski and Malia Tate on a body hidden in a wall in Eichen House's basement, they asked if it was Kira's grandmother and were shocked to learn that it was, in fact, Noshiko in 1943. This led them to deduce that Noshiko must be nearly ninety years old, forcing Noshiko to confess that, as a nine-tailed Kitsune, she was closer to nine hundred years old.
Kira, upset that she has been lied to for months by her parents, demanded that Noshiko tell them everything about what has been going on in Beacon Hills. Noshiko unsheathed the sword, revealing that the blade had been broken close to the hilt, and dumped the broken pieces of the blade onto Ken's desk before admitting that the katana had been shattered in a battle with the Nogitsune in 1943. When Kira and Scott figured out that this has all happened before, Ken reminded them that "those who cannot remember the past are condemned to repeat it" and that it started at Camp Oak Creek, a Japanese internment camp not far from Beacon Hills where Noshiko was held during World War II.
Noshiko, trying to get out of telling the full story, encouraged Kira to help her reassemble the broken pieces of the katana blade, insisting that it was a task that needed to be done in the daylight. However, Kira refused to do so until Noshiko told her the entire history between her and the Nogitsune, a demand that she reluctantly complied with after Ken took Kira's side. Looking at Scott, Noshiko pointed out that Foxes and Wolves tend not to get along, and not just in fables and stories, but Ken interjected that all allies should be welcomed during times of war.
As mother and daughter worked to reassemble the katana blade, Noshiko explained the history of their current situation, including how she stole supplies for her fellow internees, her friendship with another internee Satomi Ito, and her romantic relationship with Corporal Rhys, a medic who worked at the camp. Kira, frustrated, interrupted and told her that they weren't interested in her "Casablanca story"-- they wanted to learn how to save Stiles from his possession by the Nogitsune. Scott, knowing that Noshiko was stalling until sundown when her Oni demons could begin hunting Stiles again, pointed out that they didn't know for sure that Stiles was truly gone, but Noshiko maintained that once she finished her story, they wouldn't want her to call the Oni off.
Noshiko's story about her relationship with Rhys segued into how the two of them caught the camp doctor, Dr. Liston, and two of the MPs, Merrick and Hayes, were stealing medications from the camp and selling them on the black market. Overwhelmed by emotion, Noshiko didn't realize that she was clutching a piece of the katana blade so tightly in her hands that she began bleeding until Ken and Kira pointed it out. However, when Kira went to tend to her cut hand, Noshiko wiped her palm with a handkerchief and revealed it was completely healed. Noshiko went on to explain that Accelerated Healing was one of their gifts as Kitsune, as Kira may have noticed that she has never gotten sick in her life.
In the flashbacks to 1943, Noshiko was seen confessing what she knew about the stolen medications to the rest of the internees after a pneumonia epidemic spread through the camp. She believed that they could simply go to the administration and issue a formal complaint, but the other internees were not so optimistic that the camp employees would play fair. Though Noshiko's intentions were merely to encourage transparency in the government, the anger felt by the rest of her fellow campers, especially in light of the multiple deaths from pneumonia quickly grew out of control. A riot soon broke out among those in the camp, which ended in the MPs shooting and killing dozens of internees, and Rhys being hit with a Molotov cocktail by Satomi, who was revealed to be a Beta Werewolf. Rhys ultimately died from his wounds due to the fact that Dr. Liston had sold the camp's morphine, and Noshiko was gravely injured by dozens of gunshots.
Noshiko's role in the return of the Nogitsune was then explained to Kira and Scott; Noshiko, devastated by what had happened to her innocent fellow internees and her lover, Rhys, was so injured that the MPs believed her to be dead as well. She was put in the back of a truck with the other deceased internees and was driven out to a field where the MPs planned to burn the bodies. Noshiko, knowing she was too weakened from trying to heal to be able to fight them off, prayed to her ancestors for kitsune-tsuki, or possession by a Fox spirit; her intention was to have a Nogitsune, a Void Kitsune who feeds on chaos, strife, and pain, possess her and imbue her with the power needed to get revenge on those running the camp who massacred her people and intended to cover it up. Unfortunately for Noshiko, Kitsune can often have a dark sense of humor, and the Nogitsune ultimately chose to possess Rhys' corpse instead.
When Kira and Scott asked her what happened next, Noshiko explained that the Nogitsune, who got a head start due to Noshiko's still-weakening body slowing her down, went on a rampage at the camp and killed the rest of the survivors, both internees and employees alike. This forced Noshiko to take up her katana and chase the Nogitsune down to the tunnels under the camp, where she was joined by the Werewolf Satomi and ultimately slayed the Nogitsune with her sword, though doing so shattered the blade.
In the present, Noshiko informed Kira that the reason why she needed her to help her with the sword was because Kira, as a Thunder Kitsune, had the power to use her lightning to repair the sword. When Noshiko held out her hand and asked Kira if she trusted her, Kira reminded her that she had just learned that she was nine hundred years old, and that she wasn't sure if she could ever trust Noshiko again. Stung by her words, Noshiko silently took Kira's hand and held it above the reassembled sword blade, causing Kira's ice-blue foxfire to reforge the blade. Afterward, Noshiko handed Kira the blade and explained that her power now belonged to Kira, and when Kira wondered aloud what would happen if she didn't want it, Noshiko insisted she would need it before tossing it to her. Kira instinctively spun the sword in her hand, causing Noshiko to smile and explain that it gave her balance. She went on to say that if the Oni couldn't slay the Nogitsune, she would need to step up and do so, possibly by enlisting a wolf to help her like Satomi did.
Kira and Scott were appalled that Noshiko used this situation to condone killing Stiles and argued that she didn't give them any valuable information. Noshiko insisted that killing Stiles, and, by extension, the Nogitsune, was the only way, and Scott was shocked to see that Ken also agreed with her. Kira and Scott maintained that there had to be a way to save Stiles before leaving to go track him down.
In De-Void, Kira, going against her mother Noshiko's order to kill Stiles Stilinski in order to defeat the Nogitsune, rushed to Derek's loft with Scott McCall in order to help catch him. However, by the time they got there, the battle with the Oni Noshiko sent to kill him had already ended, with Allison Argent disarmed of her taser, Argent left with only one working gun, and Derek badly cut over his left shoulder from the Oni's ninjato sword.
Afterward, Kira went home with Scott, stating that after everything she learned about her mother the previous day, she didn't trust or feel comfortable around her or her father, who had helped keep the secrets from her. Scott offered her his bed while he would sleep in his armchair, but at Kira's insistence, the two cuddled for the rest of the evening.
In Insatiable, Kira, having witnessed Alan Deaton removing the Nogitsune flies from Isaac Lahey, Ethan Steiner, and Aiden Steiner, realized that, with it being nightfall, Noshiko would be once again going after Stiles, who was seemingly separated into an identical body by the Nogitsune, in order to figure out which one was which. She rushed to the McCall House, where she found Noshiko and two Oni standing in front of the weakened Stiles, who volunteered of his own accord to be tested for any remnants of the Nogitsune's spirit.
When Stiles assured her that he was the one who asked her to come, Kira reminded him that he would also be the one stabbed with swords before begging her mother not to go through with it. Noshiko cryptically stated that it was already done before the Oni grabbed him and began to scan him with their yellow-green glowing eyes. Fortunately for Stiles, he passed the test-- Noshiko explained that, while the Nogitsune was still affecting him, he was more him than he was the dark fox, relieving everyone in attendance. Kira and Noshiko then joined Stiles, Melissa, and Scott in a discussion about what the Nogitsune's next move could be and why he would capture Lydia Martin. Noshiko, knowing the Nogitsune best, informed them that he would only take Lydia for an advantage, which suggested that he wanted to have the power of a Banshee on his side.
Later that day, Kira and Noshiko returned home, where they continued to debate their current dilemma. Kira asked how the Oni were going to find the Nogitsune and what they were supposed to do in the meantime, leading Noshiko to pull out the strategy game Go and state "Sit and learn" as she set up the board on the coffee table. Kira was exasperated that her mother wanted to play a game during their current disaster, but Noshiko, having remembered that Scott and Lydia saw Stiles playing the game with the Nogitsune while they were in his mind, it could be a crucial detail in how to defeat him. Noshiko then went on to explain how the game worked: the game starts with an empty board, the player with the black stones goes before the one with the white stones, and the players place the stones on the board to create territories that are then captured by surrounding them.
Kira, annoyed, reminded her mother that this wasn't a game, it was life and death, but Noshiko retorted that to the Nogitsune, this was a game, and he was winning. She went on to argue that if Kira wanted to save her friends and have them survive the battle, then she needed to learn how to play the game, causing Kira to reluctantly follow her mother's lead in the game.
Later on, after the rest of the McCall Pack worked with fellow Banshee Meredith Walker to locate Lydia and prepare for the inevitable battle against the Nogitsune, Kira, having a bad feeling about what was going on, went to father Ken Yukimura to see if he knew where Noshiko was. Ken replied that while he did not know where she was, what he did know was that Noshiko had been trying to keep Kira out of the supernatural world for as long as she possibly could, to which Kira retorted, "Well, she should have thought of that before she had me magically rebuild a samurai sword."
Ken laughed and admitted that he knew that this information was all very strange to her, but insisted that she was going to need to learn a lot very quickly. Kira jokingly asked if that meant learning how to play board games, and Ken explained that in Korea, they call "Go" "Baduk" before detailing the different methods of play, including aggressive, passive, and orthodox. When Kira pointed to their game board and asked if he knew who was who, Ken replied that he knew Kira had the black stones, as the novice players always go first in the game. Kira nodded in confirmation and explained that the white stones were meant to represent the Nogitsune, which caused Ken to frown in confusion. Kira picked up on his hesitation and asked him what it was about, leading Ken to admit that the white stones were set in an aggressive style of method, which was Noshiko's manner of play, before asking Kira if she was sure she was supposed to be playing against the Nogitsune.
Figuring out that Noshiko intended to kill the Nogitsune that evening, Kira brought Scott, Stiles, Allison, and Isaac Lahey to Camp Oak Creek, where Noshiko had arrived with all five of her Oni. Scott and Stiles split away from the group in order to locate Lydia while Kira, Allison, and Isaac got into a stand-off with Noshiko, who wasted no time ordering Kira to leave and to take her friends with her. Kira insisted that she could not before pointing out that, upon really examining their game of Go, she realized that she was actually playing Noshiko and not the Nogitsune.
When the Oni teleported away to find the Void Kitsune, Allison aimed her bow at Noshiko and demanded that she call the Oni off. Noshiko scoffed at the thought that they could take the Nogitsune alive and save Stiles, and when Kira asked her, "What if we can?", Noshiko reminded her that she tried something similar seventy years ago and that it didn't work, making it clear that she believed Stiles to be truly gone. Kira, not convinced, retorted that Noshiko didn't know that for sure, and to question it would be to admit that if Stiles didn't have to die, then her former lover Corporal Rhys didn't have to die, either. Noshiko smirked sadly before remarking that she was no longer the Fox now, Kira was, but added that the Nogitsune was her demon to bury.
Unfortunately, before the argument could go on any further, the Nogitsune used the kaiken, or Kitsune tail he had stolen from Noshiko to steal ownership of the Oni, causing them to become loyal to him instead. This then caused a battle to break out between the five Oni demons against Kira, Isaac, and Allison, as Noshiko was no longer armed and was forced to watch from the sidelines. Kira managed to get through the battle without harm, but both mother and daughter were awestruck when Allison managed to actually kill an Oni by shooting it with a silver arrowhead, and their awe turned to horror when they saw another Oni drive its ninjato into Allison's chest, killing the human Hunter within minutes.
In The Divine Move, after the fight at Camp Oak Creek between the Nogitsune/the Oni and the McCall Pack/Noshiko Yukimura, Noshiko, Kira, Ken and Stiles Stilinski returned to the Yukimura House to process what had just happened and figure out how to proceed.
Noshiko brought Stiles a cup of tea, which he assumed was magic, but she assured him it was just chamomile and promised that it would calm him. Before they could speak further, Ken anxiously pointed out that Stiles wasn't safe there at the house, but Noshiko argued that they he wasn't safe anywhere. Kira brought up the fact that Allison had managed to kill an Oni before she died and wondered if that meant something, forcing Noshiko to admit that she wasn't sure how it was possible but that it certainly was. Stiles turned the topic of conversation back to the fact that Allison was killed before sadly stating that the only other good news was that it seemed like he was dying, too.
Noshiko gave him a sympathetic look and informed him that the Nogitsune made a powerful move by separating the two of them, allowing the Nogitsune to continue his plans with Stiles' face while leaving Stiles himself in a magically copied body. Kira, who was fidgeting with one of the stones from the Go board that she and Noshiko had left set up, purposefully set a piece back down on the board and asked what their move was going to be. Ken grimly replied that, at this point in the "game," they would need a "divine move;" Noshiko went on to explain that in Go, a "divine move" was a truly inspired or out-of-the-box move that changes the entire course of the game around, adding that since the Nogitsune currently had sente, or the advantage, they would need a Hail Mary-type move to turn the outcome in their favor.
Just as Stiles asked if anyone was feeling divinely inspired, Kira remembered that her mother had told her that she had originally trapped the Nogitsune in its fly form in a glass jar and brought it up. Noshiko, not sure where she was going with this train of thought, confirmed that this was true, but corrected her on the fact that it wasn't the glass jar that contained the Nogitsune-- it was where she buried it. Stiles realized she was talking about the roots of the Nemeton, which Noshiko confirmed before confessing that she didn't know much about it. When Kira asked who did know more about the Nemeton, Stiles suggested Alan Deaton, leading Kira and Stiles to head to the Beacon Hills Animal Clinic to see what they could learn from him, not knowing that Scott and Lydia were already there.