Mashirao Ojiro/Relationships

Toru Hagakure
They are teamed up together as Team I during the Battle Trial Arc.

Afterwards, they are often seen talking with each other.

After the villains retreat during the U.S.J. Arc, Toru commends Mashirao's strength, while he asks where she was transported to. After she tells him she was in the landslide zone and mentions Todoroki's strength, he comments that he's glad she was alright. During the final part of the Sports Festival, when Mashirao wants to withdraw from the tournament event, she tries to persuade him to reconsider.

After Toru exposed Yuga Aoyama as the U.A. Traitor, Mashirao was shown consoling her as she sobbed into his shoulder, further showing that the two are close.

Izuku Midoriya
They get along well though Mashirao didn't team up with him since Izuku was a target in U.A. Sports Festival Arc. Despite that Mashirao tried to warn him about Hitoshi Shinso, Izuku also stood up for him after Hitoshi insulted him. Mashirao worried for him but was relieved he emerged from the fight victorious.

During the Vs. Hero Killer Arc, he was amazed that the latter improved on his quirk and overcame his drawbacks.

In the training camp, he tried to comfort Izuku about being the only one that didn't have a partner.

When Class 1-A was attempting to bring Izuku back to U.A., Mashirao brought up the Sports Festival, remembering how Izuku had gotten angry on his behalf and exclaiming that he'd never forget what he did.

Denki Kaminari
Mashirao sits in front of Denki in class and the two are often pictured talking to each other in the background, implying a friendship.

As time goes on, they have become close and Denki sometimes confides in him with certain things.

Denki seems to have a fixation on Mashirao's tail and often plays with it and pets the hair on the end of it.

Tenya Ida
The two were partnered up during the final exams against Power Loader. They were shown to work and get along well. During the exam, they showed trust in each other as they used the combined power of their quirks to throw Mashirao through the gate resulting in the two passing.

Kyoka Jiro
They are often seen interacting and talking with each other in the background alongside some other classmates at times such as Toru Hagakure or most of the time, Fumikage Tokoyami. They have also shown splendid teamwork during their ambush against Nine in My Hero Academia: Heroes Rising. Kyoka was also seen shouting out Mashirao's name in concern when he was taken out by Nine. They seem to be good friends as well.

Yuga Aoyama
Although they aren't seen together often, it can be assumed that Mashirao and Yuga get along as classmates. During the U.A. Sports Festival, both of them end up on Hitoshi Shinso's team along with Nirengeki Shoda, and fall under the effects of his Brainwashing Quirk.

Like the rest of his classmates, Mashirao was deeply shocked to learn of Yuga being a spy (albeit unwilling) for All For One. When he and his parents were brought in for interrogation, Mashirao questioned Yuga on what he would have done had Toru not exposed him. His words caused Yuga to express his guilt at what he has done.

Hitoshi Shinso
Mashirao resigns from the tournament event in the Sports Festival due to being manipulated by Hitoshi, wanting to save his pride and dignity by doing so. As a result of Hitoshi's action, Mashirao has come to dislike him because he prevented him from doing his best. When Hitoshi approaches Izuku, Mashirao warns Izuku not to respond to his provocations.

After several months, Mashirao appears to have let go of some of his tension toward Hitoshi. In a conversation with him and Izuku, Mashirao reveals he bears no ill will over the events of the Sports Festival, causing him to feel slightly guilty.

He was pleased to hear that the latter will be helping them draw in All For One with his improved Quirk.