Family#
Tensei Ida#
Tenya has a very good relationship with his older brother, Tensei. Tenya looks up to Tensei and sees him as a role model, aspiring to be like him. When he finds out that Tensei is critically injured, he leaves the Sports Festival, despite knowing he could receive a medal, and rushes to see his brother in the hospital.[1] The bond between them is so strong that Tenya decides to avenge his brother by seeking out Stain, the villain who ended Tensei's hero career. Tensei also has great respect for Tenya, calling him a "brilliant little brother", and apologizing to him for failing to live up to his expectations as his idol.
Later, during the Joint Training, Tensei shows a more positive and supportive attitude, which Tenya attributes to his brother's progressing recovery. After this, Tenya shows more determination to represent his brother, inheriting his hero name, Ingenium.[2] In a flashback, sometime after Tenya passed the Provisional Hero License Exam, Tensei is shown to be proud of his brother's progress and considers that he is ready for "tuning" his engines.[3]
Eight years after the Final War, Tensei was able to resume Hero work at Team Idaten thanks to advancements in support items, this time working under his little brother who is now leading the agency.[4]
Class 1-A#
As the class representative of Class 1-A, and thus their official leader, Tenya takes his responsibilities very seriously. While most of the class tends to be exasperated by his rigid way of leading the class and overall uptight demeanor - usually causing them to disobey his more inconsequential demands, much to his dismay - all of them value his role as a leader and are willing to follow his command whenever necessary.
Izuku Midoriya#
When they first meet, Tenya believes that Izuku is annoying and disruptive, as he could not keep silent in the entrance ceremony. He later reprimands him for making light of the prestige of U.A. High School, which earns Izuku mockery from the other exam participants.[5] However, after observing him during the U.A. Entrance Exam, Tenya is greatly impressed by Izuku's heroic actions as he saves Ochaco Uraraka instead of focusing on himself in the test.[6]
When they meet again, Tenya apologizes for his previous judgment of Izuku as he believes that Izuku had some kind of intuition that he himself lacked.[7] Along with Ochaco, Tenya is one of the first people to befriend Izuku on their first day of school, a friendship that Tenya mentions surprised him. Although he greatly respects and admires Izuku, he also views him as a rival; Tenya feels that he needs to challenge him in order to grow as a Hero.[8] However, the rivalry between them is much friendlier than Izuku's other rivalries. Tenya respects Izuku for his dedication towards a goal or task once he has put his mind to it and not giving up on said goal or task. Likewise, Izuku respects Tenya's leadership, determination, and perseverance.[9]
Over time, as they get closer, Tenya starts to become protective of Izuku. A notable example is when he joined the Bakugo Recovery Team to keep Izuku out of trouble at Kamino Ward. He even held him back from doing anything reckless against the League of Villains when All For One emerged from the shadows.[10] Another note is that Tenya was the most worried and relieved when Izuku, Ochaco, Tsuyu, and Eijiro returned from their mission to take down the Shie Hassaikai, as well as following their work on Mission: Humarise.[11][12]
During the battle between Izuku and Class 1-A, he tells Izuku that Ingenium is a Hero that will be willing to take the hand of a lost child because giving help that's not asked for is what makes a true hero, contrasting to words the latter once said to him.[13]
Ochaco Uraraka#
Since both Tenya and Ochaco became friends with Izuku, they also developed a steady friendship pretty quickly. The two mutually care for each other's well-being and both express concern when the other is put in harm's way. The two seem to trust each other a great deal and work well together as a team, although they did find themselves on opposite sides during the U.A. Sports Festival's Cavalry Battle. During the Cavalry Battle, Tenya surprises Ochaco with Recipro Burst, with Ochaco playfully pestering Tenya afterward for concealing his abilities which caused Tenya to profusely apologize.
Tenya, like most of Class 1-A, is also accustomed to Ochaco's usual cheery demeanor, and as such becomes somewhat unnerved by Ochaco's determination for the then-upcoming Sports Festival. Tenya and Izuku are the only students Ochaco is comfortable sharing her reasons for wishing to become a hero with, and Tenya, like Izuku, believes that Ochaco's goal is a noble one. Tenya believes that there’s no shame in her quest for wealth, even before discovering it was only due to Ochaco's wish to improve her parent's lives.
Tsuyu Asui#
Tenya and Tsuyu are also shown to be friends since they are seen sitting at lunch together, and both hang out with Izuku and Ochaco. The two care about each other's well-being, shown when Tsuyu discouraged Tenya and the others from rescuing Katsuki, due to the risks associated with the mission. Tenya was apologetic for putting Tsu through stress and promised to never worry her again.
Katsuki Bakugo#
Because of their equally forceful personalities and very different personal values, Katsuki and Tenya do not get along well. Katsuki looks down on Tenya's privileged background and dislikes being ordered around by him, whereas Tenya disapproves and frequently reprimands Katsuki for his improper behavior, questioning his intentions to become a hero. This is especially apparent when they are forced to partner up for the Battle Trial.
Despite their bad standing, Tenya joins some of his classmates in saving Katsuki from the League of Villains. It is unknown what sort of standing they have now since this experience.
Momo Yaoyorozu#
Tenya and Momo are classmates and friends; they often work together to watch over and guide their class as the class president and vice-president of 1-A respectively. They have been seen working together to manage activities such as during preparations of the U.A. School Festival. They both respect each other's leadership and insight and discuss matters related to their class or Hero matters from time to time, as they did in Class 1-A's Hero office.[14]
The first time they interact, Tenya feels honored that Momo explained how Tenya was successful during the Battle Trial. They also went on to work together during the U.A. Sports Festival's Calvary Battle, wherein Momo complimented his participation. While Tenya opposed plans to save Katsuki from the League of Villains, he was surprised that Momo agreed to help, being visibly disappointed in her choice.
Shoto Todoroki#
Tenya and Shoto get along well. At first, their relationship is only by mutual agreement, where they formed a team to advance in the U.A. Sports Festival. Later, during the tournament, Tenya loses against Shoto in their battle, although he does not bear a grudge as a result of it.
Later on, a proper friendship begins to form during the Hosu Incident. Shoto realizes that Tenya is seeking revenge against the Hero Killer for severely injuring his older brother, Tensei. During the battle, Shoto calls out to Tenya with strong words to set him on the right path, and together with Izuku, they cooperate to defeat and arrest Stain. Later, Tenya thanks Shoto and Izuku and apologizes for his behavior.
Their relationship has improved over time. During the Joint Training Battle, before their match against the Class 1-B team, Tenya is the only one of their team who realized that something was bothering Shoto, which surprised his teammates, who wondered how he knew that Shoto had something on his mind considering Shoto's expression rarely changes.
After their match against the Class 1-B team ended in a draw, both students try to support each other.
During the Final War, both boys, along with the Flaming Sidekickers, are teamed up together in order to take on Dabi and the other Villains. After Dabi's first defeat at the hands of Shoto's Great Glacial Aegir, Tenya is shown comforting him after the physically and emotionally draining battle.
When Dabi is about to explode at the Gunga Mountain Villa Ruins, Tenya and Shoto show impeccable teamwork and synergy with their Quirks as they fly from Kamino Word to the detonation site using Maximum Speed. As Shoto makes it to the site and begins running towards Dabi, Tenya thanks him for the help in putting him on the path to become the Hero he truly wants to be.
Mashirao Ojiro#
The two are partnered up during the Final exams against Power Loader. During the exam, the two show trust in each other and great cooperation skills as they use the combined power of their Quirks to throw Mashirao through the gate, resulting in the two passing.
Minoru Mineta#
Tenya is usually the first to chastise Minoru for being an unabashed pervert. Minoru, in turn, views Tenya as a killjoy, prudish, and a nerd. During Minoru's attempt to peek on the girls through a peephole in the locker rooms, and later scaling the hot spring wall to see them naked, Tenya is the only one of the boys to openly protest against Minoru's indecent behavior and tries to stop him on both occasions. Tenya also stops Minoru from taunting Shoto on failing the Provisional Hero Licensing Exam.
Despite this, due to their friendships with Izuku, Tenya and Minoru are often seen with each other, and mostly appear to have a neutral if not friendly relationship. Tenya also commended Minoru and Denki on reserving the pool for endurance training, not knowing that their only intention was to see the girls in their swimwear.
During Izuku's return to U.A. while Ochaco pleads with the citizens protesting Izuku's entry, Minoru attempts to run up to Izuku, only for Tenya to stop him upon seeing that it isn't their place, as Kota Izumi and the woman Izuku rescued run up to console him.
Other schoolmates#
Mei Hatsume#
Tenya doesn't like Mei for taking advantage of his noble nature and sportsmanship in the U.A. Sports Festival, when she tricks him into to promoting her inventions during their battle. This dislike still remains with Tenya, despite her apologizing, as seen in their second encounter.
His disliking for Mei escalated when she forgets and dismisses his name, while also making him unwillingly use one of her inventions that he rejected, going as far as to call her a "madwoman". He openly voices his disliking of her to Power Loader, although Mei simply does not seem to care.
Despite their rough foundation, Mei, like always, is still open and eager to give Tenya advice and guidance on upgrades to Hero costume. Later during the construction of the Coffin in the Sky, Mei gives Tenya a new set of armor for his costume, after it was destroyed when he and the rest of Class 1-A went to retrieve Izuku.
Pro Heroes#
Manual#
Manual sends in a nomination for Tenya because he felt he could relate to him on some level, although he is surprised that Tenya accepted his invitation as having better options. He later deduces that Tenya only accepted the nomination in order to search Hosu for the Hero Killer, and his grave aura makes Manual slightly uncomfortable at first.[15][16] Manual's suspicion eventually proved to be right, with Tenya leaving to confront Stain and avenge his brother.
Tenya ignores Manual's warnings against pursuing vengeance and is scolded for it after the incident. In the end however, Tenya profusely apologizes and promises not to repeat his mistake, putting them on good terms once again.[17]
In the second round of the Work Study program, Tenya worked under Manual and his agency again, with the experience teaching him to be more flexible.
Civilians#
Kota Izumi#
When Izuku came up to Kota to say hi and introduce himself, Tenya scolded the boy when he responded to Izuku's friendliness by hitting him in the crotch. He was also surprised by Kota's vocabulary when he said that he didn't want to hang out or spend time with any "wannabe Heroes".
Villains#
Stain#
Tenya despises Stain, the Villain who severely injured his older brother Tensei, and ended his career as a Hero after crippling Tensei from the waist down. Tenya seeks out Stain in Hosu during his workplace experience and confronts him in a rage. Stain first regards Tenya as a child and tells him to leave but then sees the vengeance in him and compares him to the "fake heroes" that he desires to purge from society. He then scolds the young hero over his selfish desires of revenge over saving the Pro Hero he was about to kill.
Despite the fact that Tenya will never forgive him for what he did to his brother, he acknowledges that Stain was right about him and learns from his mistakes, resolving to start over as a hero. He also understands why some people start to admire Stain despite his criminal past.