Izuku Midoriya/Relationships

All Might
Izuku has always admired All Might since he was a small child and wanted to be 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 choose him as his successor as the "new" All Might. 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.

Shouta Aizawa
Shouta treated Izuku with disrespect at first because he saw through his "Quirk" saying he doesn't have what it takes to be a Hero. After seeing his potential in fights against Katsuki and Shouto, 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.

Recovery Girl
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 Bakugou
Izuku and Katsuki have known each other since they were very young, but they cannot be considered friends. Upon being bullied by Katsuki his whole childhood and hating his guts, Izuku began to admire everything about him, as Katsuki had everything that he didn't. 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. Despite Katsuki's antagonism towards Izuku, Izuku still has respect for Katsuki and is still shown to care for Katsuki, as shown when Katsuki is captured by the Vanguard Action Squad, Izuku uses all his strength in an attempt to save Katsuki and spiraled into despair after he failed to do so.

Ochako Uraraka
Ochako was the first new person Izuku interacted with when he first came to Yuuei. Izuku has a great friendship and camaraderie with Ochako; they get along very well and their discussions are always bright and friendly. It is implied that Izuku has a crush on Ochako, as he constantly blushes when ever she is with or near him and even started to like his once a demeaning nickname "Deku" when she said she liked the nickname. At the Sports Festival, Izuku was moved to tears to see that Ochako would team up with him even though he is worth a huge amount of points. Before Ochako's battle with Katsuki, Izuku offered to give her a strategy against Katsuki. When Katsuki accused Izuku of helping Ochako strategize against him, Izuku defended Ochako, saying that the strategy she used against him during their match was her doing.

Tenya Iida
Izuku first thought that Tenya was a scary guy and that they wouldn't get along together, but as he got to know him better, he found out he was a friendly guy 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 his successor Tenya, knowing that he has better leadership qualities than him. After Tenya was defeated by Shouto, Izuku was saddened to see his friend lose. Since Izuku knew that Tenya has a grudge against Stain, Izuku tries to save Tenya from his death. While recuperating at Hosu General Hospital, both Izuku and Tenya resolve to become stronger together.

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 Shouto defeated Izuku in the Sports Festival, Tsuyu went to Recovery Girl's office to see if Izuku was fine or not.

Shouto Todoroki
Shouto 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 Shouto, admitting that Shouto is far stronger than him. After hearing Shouto's tragic backstory and seeing his sadness, Izuku started to show sympathy for Shouto's pain and resolved to help Shouto overcome his dark past by getting him to use his fire power, telling Shouto that the fire power belongs to him and not his father. Although Izuku lost to Shouto while trying to help him, Izuku's actions did have an impact on Shouto, as he has stopped rejecting his fire power. After the battle with Stain, Izuku and Shouto are on friendlier terms with each other.

Kouta Izumi
Izuku did not get along with Kouta due to their different circumstances and ideals. However, after Izuku saved Kouta from the Muscle Augmentation villain, Kouta respects Izuku more. At first, Kouta 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 Kouta was to him, both being "Quirk-less" (Izuku not being born with a Quirk and Kouta refusing to use his Quirk), Izuku took it upon himself to save Kouta from the Muscle Augmentation villain at all costs, even going past his Quirk's limitations. During the battle, Kouta used his Quirk out of desperation in an attempt to help Izuku. After the battle, he tells Kouta that his parents died to protect everyone and says he risked his life for him because he wanted his acknowledgement as a Hero. Izuku then tells Kouta to help save everyone just as he helped save him.

Stain
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 on 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.