Mirio Togata/Relationships

His father
Mirio has an excellent relationship with his father. When Mirio expressed his desire to become a hero, his father warned him that his family's Quirk made it difficult for them to become Heroes, which is why his father gave up on becoming one. Despite the warning, Mirio did not give up on his desire, and his father supported him at all times, in spite of his former views.

Tamaki Amajiki
Mirio and Tamaki are childhood friends and have spent most of their lives together, inspiring and supporting each other. They both have a strong bond and refer to each other by their first name, which indicates their level of closeness and respect. Also self they take care and worry when one of them goes through dangerous or emotionally stressful situations, even going so far as to determine what the other would do in a situation and how they would act.

They met when Tamaki transferred to Mirio's school in third grade. Tamaki was unable to insert himself into any group due to considering himself a boring person, but Mirio came over to talk to him and asked if Tamaki had been trying to talk about heroes in his presentation and if so who his favorite hero was. It was this recognition that began the friendship between Tamaki and Mirio.

Tamaki is thankful that Mirio came to talk to him that school day and one day in high school, they were both walking home and Tamaki told Mirio that he was amazing and began to praise Mirio's optimism while lamenting his own lack of self esteem, telling him that he would become a Hero like the sun. Mirio interrupted Tamaki and told him that he could give it his all because he was by his side. Mirio encouraged Tamaki by telling him that he admired him because despite his insecurity and anxiety never ran away and inspired him to do the same, thinking that he needs to work harder to never lose to him.

Mirio continued to praise Tamaki and told him that he has amazing power and that although he had a low opinion of himself, he always thought of him as a cheerful and funny boy who is someone even more amazing than the sun. It is highly implied that after that conversation, Mirio may have given Tamaki his hero name, Suneater. Tamaki idolizes Mirio's outgoing personality and tenacity to stay motivated and keep his head balanced, something Tamaki believes he does not possess and it is often seen of Tamaki referring to Mirio as the sun, as in his eyes, Mirio shines bright like the sun because of his bright and positive personality. Mirio, on the other hand, says Tamaki shines even brighter than the sun itself, thus overshadowing it.

During Mirio's fight against Class 1-A, Tamaki is in a corner thinking how inexperienced the students are for not acknowledging all the hard work Mirio needed to refine and master his Quirk, commenting that Mirio has always been strong since he was a child but that he needs to learn to contain himself. At Sir Nighteye's meeting, Mirio showed visible concern when she learned that Tamaki had been attacked and quickly asked if she was okay. Tamaki was surprised to see Mirio so depressed after the meeting, being the first time he had seen him so depressed and asked him to raise his head. Tamaki smiled happy after watching Mirio regain her cheerful and energetic personality.

As Eri's rescue mission begins, Tamaki had begun to go a tangent about how the heroes would not be able to save Eri or even themselves and Mirio got in the way of his ramblings with words of encouragement, both to reassure Tamaki and to encourage him to action, telling him that that will not happen and that he is Suneater. When Tamaki decides to stay behind to fight three members of the Eight Bullets, he asked Izuku to take over for Mirio because he could act recklessly and he knows he is going to try too hard. During Tamaki's fight, he remembers his past with Mirio and the words he said to her back then, giving him enough motivation and strength to keep fighting and to win.

While Mirio faces Overhaul, she had different memories of him with Tamaki and that after Nejire explained that the three of them are known as The Big 3, Tamaki tells Mirio that he knew this would happen all along. After Mirio was shot by Shin Nemoto with the Quirk-Destroying Drug bullet, Tamaki woke himself up out of unconsciousness and felt something bad happen to Mirio, it is implied that right after that, Tamaki went looking for him and kept carrying him all the way out of the Shie Hassaikai's lair and carried Mirio out of the building until he was taken to the ambulance.

At some point before the operation against the Shie Hassaikai, Fat Gum joked with Tamaki after he mentioned that he had never had a fight or argument with Mirio for as long as he’s known him, which claims the two were never on bad terms.

When bringing up the topic of Eri's Rewind Quirk, Tamaki placed his hand on Mirio and mentioned Mirio's Quirk possibly returning as the latter smiled at his friend.

Nejire Hado
While they are not on a first name basis, the two have known each other during their time at U.A. and both show concern for the other in difficult situations. Since the and nejire have similar energetic personalities this often conflicts with Nejire's talkative attitude, much to her chagrin. However, this similar personality also makes it easier for both of them to talk and socialize with each other, unlike Tamaki's quiet nature.

During his third year at U.A., Nejire told Mirio that his growth is extraordinary and tells him that he is happy that the whole school is recognizing him. After Mirio's fight against Class 1-A, Nejire wants to explain Mirio's Quirk to the students and tells them the name of his Quirk and Nejire got a little angry when Mirio didn't let her continue talking, causing Mirio to apologize to her. Nejire became noticeably concerned for Mirio after Sir Nighteye's reunion, shown when she was actively trying to cheer him up and convince him not to be too hard on himself during his depression over Eri's situation.

When Yosetsu mentioned the beauty pageant, Mirio mentions to Izuku and Eri that Nejire will participate in the pageant and Nejire was glad to see them. Nejire told Mirio that she wanted to win the Miss Con Beauty Pageant at the U.A. School Festival and he supported her and told her with confidently tells her that will win. During her performance in the contest, Mirio looked at her impressed by her performance and Nejire noticed it among the audience and was glad to see it. After Nejire wins the contest, Mirio smiled as a sign of congratulation.

During the Paranormal Liberation War, Mirio returned on the battlefield with his Permeation Quirk restored and Nejire got up to help him fight the close high-end Nomus. While they attended Best Jeanist, Mirio quickly asked Nejire if she was alright and Nejire was happy and tells him that its because he was there she was able to get back up and fight, despite being badly burned.

Izuku Midoriya
Prior to The Big 3's introduction, Mirio went out of his way to talk with Izuku. He is rather friendly to Izuku, who at first found Mirio to be strange. After witnessing Mirio's power and technique, Izuku grew to admire Mirio, even thinking that he already seems to be like a Pro Hero in the way he talks.

In return, Mirio seems to hold him in high regard as he was impressed by the latter's ingenuity and in their mock battle, despite only having just met and Izuku being a first-year. When All Might asked if Izuku was suited to an internship with Nighteye, Mirio said that he had been thinking Nighteye would like Izuku from the very beginning. Mirio is eager to help Izuku succeed, offering lots of tips and bits of advice before introducing him to Nighteye.

It is currently unconfirmed how much Mirio knows about Izuku and One For All. He seemed certain that Izuku would meet Sir Nighteye, All Might's former sidekick, and did not look surprised when the retired No. 1 hero summoned him and Izuku to ask him to intercede for the latter. Mirio also took notice of the scars on Izuku's arms, which were caused by One For All.

Izuku was visibly disturbed when he learned that Mirio's Quirk was destroyed by Overhaul, and expressed anger towards the villain for that.

After Nighteye's death, when Izuku sees how optimistic Mirio is, Izuku goes as far as to propose that Mirio could take Izuku's Quirk, indicating how Izuku believes that Mirio is truly the worthier candidate for One For All, like Nighteye had said. However, Mirio turns it down as he has faith that Eri might master her Quirk to restore his and believes in the words of Nighteye about being a hero.

Izuku is impressed by this and accepts Mirio's determination, and it seems they become closer friends afterward. The two get along and Izuku still looks up to Mirio for maintaining a smile in spite of his situation, which is something All Might also did in the face of adversity.

All Might
Mirio respects and admires All Might greatly, even after the latter lost his powers, claiming he could not help being happy after being called in by him. Some of his most outlandish behaviors are similar to the energy of All Might's public persona.

It is unknown if Mirio is aware that he was the top prospective candidate for the Quirk One for All or of the bond Izuku has with him.

Sir Nighteye
Mirio works under him for his Hero Work-Studies. Sir Nighteye views him as a full-fledged student with immense potential, making him believe that Mirio deserves to inherit One For All. Thanks to the training and experience he gained under Nighteye's tutelage, Mirio was able to master his Quirk, which made him one of the strongest students in the U.A. For this reason, Mirio holds a deep respect and admiration for his mentor.

This feeling is reciprocal. Although at first Sir Nighteye only saw Mirio as the most suitable substitute for All Might, over time he began to appreciate Mirio, becoming his most treasured student.

Nighteye's death was a serious blow to Mirio. During his final moments, Mirio ran into his death bed and begged his mentor not to leave as he still had much to learn from him. Nighteye comforted Mirio by using his Foresight Quirk one final time to tell him he'd be a great hero in the future.

Although at first he could not help but cry for his death, Mirio has decided not to be sad because Sir Nighteye was smiling all the time while talking to him and will respect his teachings by also smiling since he is going to be an outstanding Hero in the future. After his death, Mirio accept his mentor's loss.

Eraser Head
Until the Shie Hassaikai Raid, there was little interaction between the two. Mirio respects him as a teacher, and Shota recognizes Mirio as U.A.'s most powerful student, even considering him to be the top candidate for No. 1 Hero over all of the Pro Heroes.

After the rescue of Eri, the loss of Mirio's Permeation Quirk and the death of Sir Nighteye, Shota comforts a disconsolate Mirio, promising that he will look for a way to help him to recover his Quirk.

When Eri is under Shota's custody, Mirio helps him take care of her and it is common to see them together when Eri walks through the U.A. Shota is hopeful that Eri will learn to control her Rewind and thereby, restore Mirio's Permeation.

Ovehaul
Mirio knew about Overhaul from Sir Nighteye's research and was aware of his connection to the Shie Hassaikai and the danger he posed. Mirio met Overhaul in person when he was patrolling with Izuku and tried to avoid combat by feeling a murderous air from him, while telling Izuku that they should leave and allowing Eri to return with him.

While the heroes were doing investigations, Mirio and Izuku both agree they have to stop Overhaul and save Eri from him.

Mirio faced Overhaul alone and gave up nothing to try to stop him. Mirio was angry with him and quickly attacked him after defeating Deidoro Sakaki and Shin Nemoto, Overhaul dodged his attack and started threatening Mirio while calling Eri a curse, making Mirio even more angry.

Mirio dodged Overhaul's attacks during their fight and left him unable to defend himself, declaring that he would defeat him and never hurt Eri again. Overhaul is enraged when Mirio says his real name and orders Shin Nemoto to shoot Quirk-Destroying Drug ​at Mirio.

Despite being hit by a Bullet and having lost his Guirk Mirio stood up and hit him screaming that he will always be Lemillion. Even with serious injuries, he did not give up and kept filming against the Villain, until Izuku's arrival. Sir Nighteye even deduced that at some point Mirio came to scare Overhaul.

Eri
Mirio met Eri while he was on patrol with Izuku, although they do not react well. Mirio let her return with ​Chisaki and decides to follow Sir Nighteye's orders. When Mirio finds out about what was happening to Eri, he blames himself greatly and becomes determined to save her.

When Mirio managed to reach Chronostasis and Overhaul, Mirio was able to hold her in his arms and told him that he would be his hero. Mirio was doing everything possible to prevent Chisaki from hurting her and she sacrificed her powers to do so, promising that she would never feel more pain. He showed no regret in his choice as it allowed him to get her to safety.

Due to his actions and words, he was the first person who gave Eri hope that she could be free from Overhaul and the Shie Hassaikai. Mirio even had the faith that her Quirk could possibly restore her lost powers, but she was in no rush to get them back and told Izuku that she would smile because she didn't want Eri to feel guilty about her condition.

Later while visiting her at the hospital, he comforts her by telling her that nothing that happened to her is her fault and invites her to the School Festival to have fun for the first time. During the Class 1-A performance, he holds her up in the air so she can see Izuku dance and cries with joy to see her smile at the performance.

The two have had a great relationship ever since, as it has been said that he is very good friends with Eri. She admires him and he acts like a brotherly figure to her. They are often seen walking around the U.A together and at some point I help her write a letter to Izuku.

When Eri was able to use her Quirk successfully after training with insects and lizards, Mirio wanted to help her friends and fellow heroes in the operation against the Paranormal Liberation Front so he asked her if she could use her Quirk on him. He initially apologizes for taking advantage of Eri but due to the kindness he showed her, Eri claimed that she had been training to help him. In the fight against Tomura, Mirio internally thanked Eri for allowing for allowing him to be a Hero again.