Born into the prestigious Nakiri Family, and the wielder of God's Tongue, Erina Nakiri has a huge influence in Tōtsuki as the top prospect of the 92nd Tōtsuki Generation. Because of this, she is worshiped and feared by many. This has had the unfortunate side-effect of limiting Erina's ability to make companions, something which she has only recently begun to overcome.
Family
Senzaemon Nakiri
Patriarch of the Nakiri Family and the prime founder of the Tōtsuki Organization, Senzaemon is Erina's maternal grandfather and a living legend in the culinary world. It was Senzaemon who rescued Erina from her father's abuse, taking legal custody for the remaining duration of her childhood. Erina holds deep respect for her grandfather, tending to see him as an authority figure rather than a family member. Senzaemon has faith in Erina's abilities and grants her considerable freedom, but regrets that he is unable to undo the effects of Azami's abuse on his own. After defeating Azami and Central, Senzaemon announced his retirement and entrusted Erina to become the new Headmaster of Tōtsuki.
Mana Nakiri
Mana is the biological mother of Erina as well as the bookmaster of WGO. Not much was known about the relationship between the mother and daughter, however Erina reveals that Mana is in control of BLUE and had set Erina's bracket to match against one Noir Chef after another. Erina seems quite angry at this setup as she believes Mana no longer cares about the "weak" chefs and uses her to take them all out, leaving the "superhuman" chefs left in the competition. However, Erina also insinuates that Mana no longer needs her daughter's "God Tongue", which leaves Erina to declare that she will use her superhuman ability to take over BLUE by showing her true power.
Due to Mana abandoning Erina during her childhood in order to pursue her own goals and being fundamentally absent during her life, including during her father's torturous training regimen, Erina deeply resents her mother. Her anger is such that, during the BLUE, Erina reverted to an state of being colder and crueler than how she used to be.
Azami Nakiri
Azami is the biological father of Erina. When she was young, her father decided to teach her some cooking skills by subjecting Erina to a brutal training regimen. This included forcing her to compare dishes and then throwing away all the contents of the dishes that were considered inferior. Azami was not above using physical force to ingrain his doctrine of food into his daughter, if Erina showed any sort of resistance, nor did he have any qualms about cutting her off from the rest of the world. It was because of this that Senzaemon disowned him and exiled him from the Tōtsuki Culinary Academy. The abuse that Erina suffered caused her to develop a severe fear of her father, leaving her terrified whenever she was in his presence. Unlike her normally confident and haughty self, she would be completely timid and submissive to her father's actions and requests, even if it is not what she wished to do.
However, with Sōma and the others' help, Erina finally mustered the courage to resist her father and relinquished her status as the 10th seat of the Elite Ten in order to fight alongside Soma and the others, surprising Azami. Erina was able to finally silence her father with her own cooking, as well as showing her true act of rebellion by acting like Sōma, seeing the young man as her new reason to become a great chef.
Alice Nakiri
Alice is Erina's maternal Danish cousin. The two cousins grew up together as they were both a part of the Nakiri family and actually had a very friendly relationship. Erina was a bit mean to her in their childhood and Alice has used such experiences as a subject to teasing her cousin in the present. Nevertheless, Erina was generally happy to be with Alice and even wanted to communicate through the mail when she moved to Denmark, though this endeavour was ultimately stopped by Azami. In the present, Erina holds some respect towards her cousin and acknowledges that she is a skilled cook, but still nowhere near her level. Alice, in turn, loves to poke fun at her cousin at any opportunity. Erina is more than willing to hang out with Alice, such as their pool outing. At the very least, their familial ties are strong, but partially fueled by a rivalry founded by a common respect for the other's abilities and talent.
Leonora Nakiri
Leonora is Alice's mother and Erina's aunt. Because of the similar personalities of Alice and her mother, Erina finds her aunt a bit annoying at times. However, like her grandfather, Erina does hold respect towards Leonora and her abilities.
Tōtsuki Culinary Academy: Elite Ten Council
Sōma Yukihira
The current 1st Seat of the Elite Ten. Erina's former arch-nemesis who hails from the humble Yukihira Diner, Sōma is Erina's main rival. Erina was the Elite Ten member who supervised the Entrance Exam that Sōma applied in. Erina quickly deemed Sōma a second-grade cook due to his diner background, and was initally insulted by the outward simplicity of his dish. While Erina was impressed by Sōma's dish, but a mixture of her pride and Sōma's cocky attitude led her to deny him entrance to the school. To her shock and fury, her decision was overriden by Senzaemon, and Sōma joined her as part of the 92nd class. Erina went out of her way to make Sōma's life at Tōtsuki as difficult as possible, or at least try to remind him of their difference of status. Unfortunately for her, her attempts at intimidation were ineffective against the happy-go-lucky Soma who either ignored her insults or, due to his denseness, misunderstood what she's trying to say, further infuriating Erina. Any mention of Sōma's name or merely being in his presence would send Erina into a state of frustration and anger to the point that Hisako would avoid referring to him as much as possible.
Despite Erina's hostile behaviour to Sōma, Sōma himself showed no hostility towards her, having a one-sided friendly attitude to her. At times though, Erina does acknowledge that Sōma is skilled, though she still views him lower than her due to her pride. Erina was unaware that Sōma is also the son of her idol, Jōichirō Saiba, though she did once see a visage of Jōichirō over Sōma. His relationship to Jōichirō is inadvertently revealed to her when she walked in on a conversation between her father and Sōma. At first, she was in disbelief but realized it was true after seeing the two next to each other in a recent photo. She became greatly shocked after realizing that she had been hostile towards the son of the chef she always admired.
After Sōma gave her a taste of true Yukihira cooking, Erina has become much more friendly to Sōma, enough so to give him personal lessons in order to prepare himself and the other 92nd Generation standouts in order to pass the Promotion Exams. She tends to talk more personal things with Soma when they're alone and she no longer gets angry when she sees him or when someone mentions his name. She even laughed at some of his antics.
During her match with Momo, Erina seemed to have used Sōma as inspiration to make a dish through innovation and even used his victory catchphrase after winning her match. Sōma noticed this and teased her about it, only for Erina to react defensively. While the two can function as a team, they also tend to clash and butt-heads whenever one or the other will battle their opponents. While she will not admit to it, Erina realized that she wanted to become a chef like Sōma proven on how her usual behavior quickly changed as she remade her entree dish, was that of Sōma's look of having fun. During the final bout, Erina even used Sōma's "Transforming Seasoning" for her final dish, which greatly satisfied the judges by giving them the same reaction she received from Sōma's entry dish, as well as naming her dishes on the spot and with Erina asking her father how does her new dish taste.
Following the Rebels victory, Erina angrily chastises Sōma for forcing her to make up a specialty dish in order to win, but is thankful in his faith in her as well as his efforts and contributions to help her win. Upon appointing a 1st Seat candidate, Erina chose Sōma as she believed it was his efforts, faith and innovation that led the Rebels to victory. He then nominates Erina as the new Headmistress of Tōtsuki as Sōma claims that she is still stronger than him, but also to give him a reason to challenge her in the future.
During their 2nd year, the two share a good camaraderie friendship with Sōma acting as Erina's right hand man. After Asahi's princely demeanor as well as Sōma declaring claim of Erina, she began feeling confused and flustered over the two young men fighting over her. While she may not have realized it, Erina seems to have Sōma constantly in her mind as when she was describing her ideal man to Megumi, she was actually describing Sōma. The two began speaking after Sōma became concerned about her leaving him, prompting the two to have their usual talk. While he compliments her smile, referring to her happy self as pretty, Erina became shocked and flustered while trying to maintain her focus on the task at hand. Sōma and Erina reaffirm that they will continue their journey together, hoping to stay by each other's side.
Megumi Tadokoro
Erina did not directly interact with Megumi until they were partnered at the French restaurant Excellent for the Stagiaire event. However, Erina told Megumi, she knew about her since she survived until the main tournament for the Autumn Election. Despite Erina's initial hostile warning to Megumi, she was impressed with her suggestion to let the customers choose the amount of sauce to pour on their dish, moreover, how she was able to have reached that conclusion from just washing dishes. By the end of their assignment, the two were on friendly terms.
After Megumi lost to Momo, Erina incorporated elements of Megumi's dish into her own. She even partly named her own dish after her friend, leaving Megumi crying in gratitude. Here, Erina also states her confidence in Megumi's fighting style, praising Megumi's willingness to go to new lengths in cooking by sacrificing the chance at a safe perfect point score to aim for a 120 point score.
The two became close friends during their 2nd year as the two would speak to each other about certain topics. After Erina begins to contemplate romance due to the situation with Asahi, she then asks Megumi if there is someone she likes, only for her stutter in reply that she was unsure. Erina then explains her idea of her ideal man; "Someone earnest towards his cooking. Someone that never forgets his goal of forging ahead. Just a little thrilling, but still wonderful. Someone that surpasses her expectations of him in ways she can respect him for." This led Megumi to think that Erina was describing Sōma as her ideal man.
Satoshi Isshiki
Satoshi was a fellow member of the Elite Ten Council who holds the 7th seat. Despite Erina's best attempts to deny Sōma's participation in the Autumn Election, Satoshi defended his fellow Polar Star Gang member. Erina seems to show some bitter feelings towards Satoshi due to his seemingly "blatant favouritism" with Sōma. Despite that, Satoshi seems to care for Erina as he was the one who suggested that the Polar Star Dorm throw a banquet to welcome her after hearing about her situation involving her father and when the later admitted to not having eaten dinner yet.
Ryō Kurokiba
Ryō is Alice's assistant as Hisako is to her. While they don't have any sort of relationship with each other, Ryō is one of the few students whom she acknowledges as a talented chef because Alice trusts and acknowledges him.
Etsuya Eizan
Etsuya is a fellow member of the Elite Ten Council who holds the 9th seat. Despite Erina's best attempts to deny Sōma's participation in the Autumn Election, Etsuya defends Soma's selection for Election, much to her dismay.
Takumi Aldini
Erina did not directly interact with Takumi much, they are natural to each other. While Takumi respects Erina, she likewise trusts him and his ability during the Régiment de Cuisine. The two may have become friends during their 2nd year. However, during their face-off in the BLUE, Erina was cold to Takumi, calls her own cooking "garbage" and threw her own dish into the trash, much to his shock. Their current relationship remains unknown.
It is, however, important to note that by that time, Erina was blinded by a fit of rage towards her mother and her hostility wasn't likely aimed at him per se but rather she simply spares no one who gets in her way.
Tōtsuki Culinary Academy
Hisako Arato
Hisako is Erina's closest, if not only friend and her personal secretary. Hisako handles all of Erina's business around the school and accompanies her at nearly all hours of the day. The two have known each other since they were children and quickly became best friends. Hisako does whatever she can to help out Erina and usually chastises anyone who annoys or insults Erina for her. For most of her life, Hisako was Erina's only companion, and Erina truly sees Hisako as a friend rather than an ally like Ikumi Mito. She was noticeably sad and lonely when Hisako left on her own self-imposed leave of absence and wanted her to come back as soon as possible. When they were children, Erina was disappointed when Hisako told her that she was fine standing behind her. Deep down, Erina wants Hisako to stand beside her rather than follow behind. After the Stagiaire, Hisako finally returned to Erina, however, she became curious because Hisako had suddenly become friendly with Sōma. Still, despite their tight friendship, Erina's fear of her father prevented her from not having Hisako fired as her secretary, despite her strong disagreement with his decision.
Ikumi Mito
Ikumi was Erina's associate and one of Erina's most powerful allies due to her influence in the meat business. Erina showed much confidence in Ikumi's skills enough to let her handle the Shokugeki to possibly have Soma expelled. Erina later observed her Shokugeki against Soma. Though her performance and dish was impressive and certainly could have gotten him expelled, Soma emerged victoriously. Immediately upon her loss, Erina revoked everything she gave to Ikumi and cut ties with her. Ikumi was bitter by this, but both have since shown minimal cordial behaviour around one another.
Nao Sadatsuka
Nao is Erina's stalker who wishes to get close to her. It is obvious at this point that Erina has not acknowledged her skill enough to be a member of her faction. It is not known if she even knows of her existence. Nevertheless Sadatsuka wishes to get close to her, but due to the conditions of her Shokugeki against Hisako, she is not allowed to come near Erina. Instead, she sends 30 letters to Erina every day, but none reach her due to Hisako destroying all of them.
Polar Star Dormitory
Erina sought shelter at Polar Star after she was plagued by nightmares due to the return of her abusive father to Tōtsuki. After hearing her traumatic childhood, the residents immediately welcomed her into the dormitory for the time being. Wanting to make usage of her abilities, the Polar Star residents were eager to have her sample their dishes and give critiques, which she obliged. During her time there, she has befriended most of them and personally trained them all to pass the Promotion Exams in order to take down her father.
Others
Jōichirō Yukihira
Of all chefs who cooked for Erina, Jōichirō had a profound effect on her. Jōichirō is her cooking idol and even keeps a picture of him with her at age 10 as her personal treasure. Jōichirō was the first chef to let her experience cooking as something fun, and she views him as the very image of a perfect chef. She has made a promise to Jōichirō to become a good chef, wanting him to eat her food once she becomes a great chef. Erina seems to have an extreme admiration for him as anytime she has him on her mind, she blushes. After the Tōtsuki Friendship and Rapport Training camp, Erina accidentally left a book behind in her room and went back to retrieve it since the book held her treasured photo of him. After Jōichirō returned to Polar Star Dormitory to visit his son, as he left, Erina sensed him while she was inside a car and immediately told the driver to stop. As she exited the vehicle and looked around, Jōichirō was nowhere in sight. During her summer outing with Alice, when Alice asked her if she was ever in love, Erina recalled Jōichirō as the closest thing she has to a crush, but she never mentioned his name out loud to her. During the Moon Banquet Festival, Erina personally kept the best table at her shop open all week in case Jōichirō had shown up.
Early in the series, Erina had no clue that Jōichirō was the father of her former arch-nemesis, Sōma. She was horrified that she had been talking down to and trying to expel her idol's son.
Asahi Saiba
An underground chef instigating Erina's administration. Little did she know, Asahi was trained and raised by her idol Jōichirō and had infiltrated her academy as a guest instructor under the alias Suzuki. As Suzuki, Asahi presents himself as a "prince charming" towards Erina in order to win her over and make her fall for him, which only succeeds in embarrassing her, especially after she walks in on Asahi and Sōma arguing on who will have Erina. Because of this, Erina begins to contemplate on the very idea of love or her idea of her ideal man, but wishes to focus on the task at hand. She is then abducted by Asahi himself as he plans claim Erina and her "God Tongue" for himself by publicly defeating her during the BLUE competition.