Izuku Midoriya/Relationships

Toshinori Yagi
Izuku has always admired All Might since he was a small child and wanted to be a hero just like him. After earning All Might's respect after he just ran toward the slime monster trying to save Katsuki, a mentor-student relationship bloomed between them and All Might chose him as his successor. While All Might's training on Izuku was rough, the latter continued to give it his all. They grew closer as All Might listened to his resolve of training more than he has to become a great hero, impressing the hero.

All Might is his confidante, mentor, friend in and out of school, and they share a mutual respect for each other's heroism ideals. Izuku's admiration and respect for All Might is so great that he had trouble trying to attack All Might during the End of Term Test, and when he had no choice but to attack All Might with Katsuki's Grenade Bracer, Izuku apologized.

Shota Aizawa
Shota treated Izuku with disrespect at first saying he doesn't have what it takes to be a Hero. After seeing his potential in fights against Katsuki and Shoto, and even against villains, he believes in Izuku's true power and abilities. He's also been shown to be a little stubborn about Izuku's injuries when he broke his arms twice.

Chiyo Shuuzenji
Recovery Girl is one of the few people who know about Izuku's Quirk. Often, she scolds at Izuku for using his Quirk dangerously.

Katsuki Bakugo
Izuku and Katsuki have known each other since they were very young, but their relationship has deteriorated over the years (though interestingly enough, Izuku continues to call Katsuki by his childhood nickname, "Kacchan"). Ever since failing to develop a quirk, Katsuki has seen Izuku as weak and bullied him relentlessly, giving him the name "Deku," and even going as far as to suicide bait him on one known occasion. It can be assumed that it is due to Katsuki's abuse that Izuku has such a skittish nature, stutter, and initially low self confidence. Izuku states that Katsuki makes all of Izuku's insecurities about himself bubble to the surface. Despite the two absolutely hating each other, Izuku still admires him for his strong quirk, natural combat capabilities, confidence, and ability to win. Ever since the end of the Battle Trial Arc, Izuku has not spoken to Katsuki on friendly terms due to Katsuki considering Izuku his arch-rival. Even still, Izuku still has respect for Katsuki and is still shown to care for him, as shown when Katsuki is captured by the Vanguard Action Squad, Izuku uses all his strength in an attempt to save him and spiraled into despair after he failed to do so. Directly after, Izuku teams up with Tenya, Ejirou, Shoto, and Momo in an attempt to rescue Katsuki from the League of Villains' hideout. Back at UA some time later, Katsuki and Izuku take out their stress on eachother in an emotional fight, which Katsuki wins. Since the fight, the two better understand eachother and have become more reminiscent to that of a proper "friendly" rivalry, though they are still often at odds due to their clashing personalities and overall shaky history with each other.

Ochaco Uraraka
Ochaco was the first new person Izuku interacted with when he first came to U.A.. Izuku has a great friendship and camaraderie with Ochaco; they get along very well and their discussions are always bright and friendly. Ochaco was the one that turned his once demeaning nickname "Deku" into a positive identity for him, when she said it gave her a "never gives up" vibe. There have been implications that Izuku has a crush on Ochaco, as he would constantly blush whenever she was with or near him, though there has been little evidence of this subsequent to them becoming better friends. At the Sports Festival, Izuku was moved to tears to see that Ochaco would team up with him even though he is worth a huge amount of points. Before Ochaco's battle with Katsuki, Izuku offered to give her a strategy against Katsuki. When Katsuki accused Izuku of helping Ochaco strategize against him, Izuku defended Ochaco, saying that the strategy she used against him during their match was her doing. Ochaco is also hinted to like Izuku due to the fact that she can be seen admiring him for doing the heroic things he does, wanting to be like him, and getting nervous whenever someone even hints at the idea of her having a liking to Izuku. After the Hero License Exam Arc, Ochaco has decided to focus on becoming a Hero for her sake and so that her love for Izuku doesn't interfere between them.

Tenya Iida
Izuku first thought that Tenya was scary and that they wouldn't get along, but as he got to know him better, he found out he was a friendly and they ended up becoming friends. Izuku and Tenya are usually friendly with each other. However, sometimes their friendship slightly falters such as when Izuku criticized Tenya for seeking revenge against Stain and Tenya punching Izuku in the face for acting recklessly by attempting to save Katsuki. Despite this, Izuku and Tenya's friendship have rebounded back many times despite these mishaps, mainly because they are only concerned for each other's well being. They are usually seen together having friendly discussions. Izuku resigned as Class President and named Tenya as his successor, knowing that he has better leadership qualities than him. After Tenya was defeated by Shoto, Izuku was saddened to see his friend lose. Since Izuku knew that Tenya has a grudge against Stain, he tries to save him from his death. While recuperating at Hosu General Hospital, both Izuku and Tenya resolve to become stronger together.

Shota Aizawa
Shota is Izuku's homeroom teacher. Initially, Shota did not believe Izuku can be a hero due to his ruthless behaviour when using his Quirk. However, Izuku proved to Shota that he has potential and did not expel him. Throughout the series, their relationship can be defined as a rocky, troublesome student-teacher relationship. As his teacher, Izuku listens to Shota's orders and advise in order to improve himself. He has some level of respect towards Shota, but Shota's cold and logical personality conflicts with Izuku's personality and mindset, making it difficult for the two to get along. Out of all his students, Shota appears to antagonize Izuku the most whenever he does something that upsets him, a reoccurring problem being Izuku overusing his Quirk and breaking his body. As such, Shota refers Izuku as the 'Problem Child'.

However, Shota is still Izuku's teacher and as such, ultimately cares for him. He would offer some level of consolidation and guidance for Izuku when he is upset, and he will make sure Izuku does not do anything dangerous and act upon it. This more caring and inspirational side of Shota helps Izuku get along better with him.

It is possible another reason they do not get along well is because of Izuku's personality and mindset baring similarly to All Might's, who Izuku looks up to. Since Shota and All Might do not get along (at least in the beginning of the series as the two got a little better over the course of time), this reflects with Shota and Izuku's relationship

Tsuyu Asui
Tsuyu respects Midoriya for his heroic actions as well as his victory against Katsuki. During the Rescue Trial Arc, she was receptive of Midoriya's plan to subdue the swimming villains, showing not only respect, but also trust. After Shoto defeated Izuku in the Sports Festival, Tsuyu was one of the few who went to Recovery Girl's office to see if he was fine or not.

Shoto Todoroki
Shoto saw Izuku as his arch rival due to him having connections with All Might (a person with whom his father has a major rivalry). Izuku, on the other hand, has a lot of respect for Shoto, admitting that he is a far stronger than him. After hearing Shoto's tragic backstory and seeing his sadness, Izuku started to show sympathy for his pain and resolved to help him overcome his dark past by getting him to use his power, telling Shoto that the power belongs to him and not his father. Although Izuku lost to Shoto while trying to help him, Izuku's actions did have an impact, as he has stopped rejecting his power. After the battle with Stain Izuku and Shoto are on friendly terms with each other.

Kota Izumi
Izuku did not get along with Kota due to their different circumstances and ideals. However, after Izuku saved Kota from the Muscle Augmentation villain, Kota respects Izuku more. At first, Kota despised Izuku and Class 1-A for always working so hard to better themselves against fighting villains. Because of his past, he ignored anything that dealt with Heroes and Villains, and even Quirks altogether. Izuku, after finding his secret hideout, tried talking to him only to have him snap at him because he's never gone through what he has. Because of how similar Kota was to him, both being "quirkless" (Izuku not being born with a Quirk and Kota refusing to use his quirk), Izuku took it upon himself to save Kota from the Muscle Augmentation villain at all costs, even going past his limitations. During the battle, Kota used his Quirk out of desperation in an attempt to help Izuku. After the battle, he tells Kota that his parents died to protect him and says he risked his life for him because he wanted his acknowledgement as a Hero. Izuku then tells Kota to help save others just as he helped save him.

Chizome Akaguro
Stain respects Izuku's reasoning to be a Hero and sees worth in letting Izuku live. Izuku, on the other hand, tries to save Tenya from Stain. Also, when Izuku was captured by one of the Noumu-like creatures, Stain was the one who saved him. While Izuku does not approve of Stain's methods, Izuku respects Stain for living according to his ideals and never giving up on achieving his ideal world.

Camie
Izuku and Camie appear to be neutral with each other even though they are from different schools and were enemies in the Provisional Hero License Exam; Camie has shown interest in Izuku because of his ideals and intellect while on the other hand, Izuku found Camie to be weird due to her Quirk and her shamelessness but doesn't hate her. Izuku first met Camie when he fought against her during the Provisional Hero License Exam. Their encounter made Camie incredibly interested in Izuku, wanting to learn more about him and his desires. Izuku was surprised by Camie's fighting abilities and later found her to be a scary person when she revealed her Quirk along with her growing interest in him. He even agreed with Hanta that she was a pervert when she shamelessly attacked him without any clothes, another aspect that he found surprising and terrifying.

Despite his impressions of her and the fact they are opponents with one another, Izuku was not afraid to save her despite knowing she was deceiving him. Before the Second Exam of the Provisional Hero License Exam begun, Izuku acknowledged her wishing of good luck to him.

After the License Exam, Izuku wanted to talk to Camie again, as she had more to talk about with him and his own interest in her stealth techniques. But he was disappointed when he found out she had already left.