Itsuka and Yui aren't seen together often, but they were seen together a couple times in the Forrest Training Camp. In one night of the Forrest Training Camp, Class 1-B acts as the scaring group during the test of courage. Itsuka and Juzo emerge from some bushes, and Juzo giggles and complements Yui. Itsuka also praises Yui, telling her she is doing very well, as Juzo continues to snicker. Yui stoically responds to them by saying, "Yeah". A flashback occurs, where Katsuki and Shoto were walking in the forest. Suddenly, Yui popped up out of nowhere in the softened ground, softened by Juzo's quirk. The boys (Katsuki and Shoto) stop in their tracks as they were frightened by Yui. The flashback ends and Juzo continues to snicker.
Unexpectedly, smoke starts to form. Itsuka starts to notice and asks her peers if they noticed. Juzo notes he has noticed and starts to joke that maybe Shoto and Katsuki might have set off their quirks out of fear. In almost an instant, Juzo passes out. Yui and Itsuka look from behind to see Juzo passed out on the ground. Itsuka starts to realize that the smoke is poisonous and calls out to Yui, telling her not to breath in the smoke. Itsuka uses her quirk, big fist, to save Yui by covering Yui with her giant fist. A few moments later, Itsuka is seen carrying Yui and Juzo to a safety. While Itsuka was on her way to safety, Itsuka runs into Tetsutetsu and Ibara. Tetsutetsu then tells Itsuka that Momo was nearby and had made masks for them. Tetsutetsu also told Itsuka that Yosetsu was leading some class 1-A students to safety to aid them. Then, Tetsutetsu gives Itsuka, Yui, and the unconscious Juzo masks.
In the 2nd My Hero Academia light novel, the story takes place, once again, in the Forrest Training Camp. Itsuka and Yui are seen bathing together with their classmate, Ibara in the girl's hot baths with the other girls. They were conversating, until the girls found out that a little pervert, Minoru Mineta, was watching them. Later, Yui, Itsuka, Ibara, and their classmate Reiko Yanagi, all go to the class 1-A girls sleeping area to thank the girls for rescuing the class 1-b girls from the purple-haired creep. They all have a sleepover. And also in Season 5, when Neito talks about 'Settle this once and for all today', Itsuka and Yui both are glaring at him.
ItsuYui is the most popular ship for Yui. The ship sailed after Itsuka saved Yui from the smoke in the Training Camp. Itsuka calls Yui by her first name, so there was some headcanons that they were dating. Lots of shippers thought they would be cute together. The ship is considered a rare pair, considering the fact that Yui, unfortunately doesn't get much screen time as Itsuka.
- Itsuka calls Yui by her first name, so they both seem to be close.
- In the Ultra Analysis Book, It is shown that Yui also cares for Itsuka, as Yui said she was glad Itsuka was alright after the Forest Training Camp crisis.