Class 1-B#
Neito Monoma#
Itsuka and Neito are overall friendly towards one another. However, she does not approve of Neito's constant mockery of Class 1-A. Whenever he decides to taunt them for whatever reason, Itsuka will step in, knock him out and apologize for his actions.[1][2] Although Itsuka criticizes Neito quite heavily, Neito never seems to harbor any animosity towards, indicating the friendly atmosphere between them. She also seems to enjoy teasing Neito. She turned him in during the scavenger hunt for being a perverse person[3] and taunted him about making enemies with Katsuki while patting his head.[4] It is later revealed she shares his dislike for being upstaged by Class 1-A, though she has a healthier handling of it compared to Neito.
Tetsutetsu Tetsutetsu#
Itsuka decided to let Tetsutetsu's team participate in the tournament event of the Sports Festival as her replacement, feeling that they deserved the opportunity more. She notes that Tetsutetsu is aggressive and overzealous but does not seem to think that these are necessarily bad things. This was seen when they go after the villain Mustard, as Tetsutetsu voiced that he will protect the class, Itsuka notes while he has a one-sided mind, his intentions are good. She smiled and agreed with his declaration, showing she respects him.[5][6]
Tetsutetsu also seems to value Itsuka's well-being as he rushed to her aid to protect her. The two appear to be on good terms, and unlike with Neito, the two have not been seen arguing or fighting or criticizing each other, indicating that their relationship is calmer than the one she has with Neito.
During the Joint Training Battle. Tetsutetsu excitedly spoke about Kendo to Class 1-A, stating she is the big sister of the class and keeps them all together. This further shows his respect and admiration towards her.
Reiko Yanagi#
Itsuka and Reiko are good friends. Reiko was the one who designed her outfit for the Beauty Contest and helped her to prepare for the competition. They also interned at the same place for the first[7] and second Work Studies. They are also on first name basis, indicating they are close.
Kinoko Komori#
While little interaction is seen, Itsuka and Kinoko seem to be good friends as they are seen oftentimes together, especially during team-ups. Kinoko was on Itsuka's team during the Calvary Battle at the U.A. Sports Festival and when Itsuka decided that it was fair to allow Tetsutetsu Tetsutetsu and Ibara Shiozaki to move up to the tournament event, Kinoko with no words shyly agrees.[8] It also appears that Itsuka is Kinoko’s supportive person, as Kinoko is aesthetically shown struggling to keep herself together during earlier school activities beside her, but eventually finds her charisma. Itsuka and Kinoko eventually team-up again in the Joint Training Battle during Round 2.[9] They team up with each other once again during a Team-Up Mission. During the mission, Kendo called Kinoko ‘pretty upbeat’ about the idol convention. Itsuka was also briefly concerned for her when she hesitated to attack the villains.[10]
Class 1-A#
Momo Yaoyorozu#
Itsuka and Momo interned together under Uwabami.[11] Although they were treated like Uwabami's entourage during their time together, Momo always tried to find a lesson in everything. Itsuka appeared to feel sorry for Momo, seeing that she was clearly in denial.[12]
However, the two were shown to get along, despite them being from different classes.
Months later after their internship with Uwabami, she and Momo were continued to be treated as a pair by fans. Even though she did not show it, she could not stand being continuously compared to her because the latter had better grades and a better quirk. She tells Momo about these feelings before the second round of the Joint Training Battle begins and in addition says that she has been waiting to duke it out with her for a while.[13] Despite ultimately winning the second round for Class 1-B and defeating Momo in single combat, she is not satisfied and says that it did not feel like she actually won as she gazes upon an unconscious Momo.[14]
Even with her self-declared rivalry with Momo, Itsuka still accompanies her to the infirmary while looking concerned for her. This goes to show that despite their rivalry, it's a friendly one.[15]