Kohei Horikoshi does a fantastic job when it comes to making the overwhelming majority of My Hero Academia's cast likable. Even characters who initially seem irredeemable, such as Endeavor, end up receiving a relatively well-written redemption arc where they start turning themselves around and earning fans' respect.
There are less than a handful of characters that most fans agree are annoying overall, due to the overwhelming amount of development that most of MHA's cast go through, improving their likability. However, there are plenty of additional characters that either start out irritating and stay that way, or have particular traits that some fans simply can't stand.
10 Even Other In-Universe Characters Can't Stand Mineta
No My Hero Academia character is more universally-hated than Minoru Mineta, Class 1-A's resident pervert. Everything he does, down to his sole motivation for becoming a hero in the first place, is to seem cool and attract ladies.
Nothing about his character suggests that he's intelligent or powerful enough to have made it into Class 1-A. To make matters worse, there are plenty of characters in both Class 1-B and the Support Course that fans would much rather see take Mineta's spot in U.A.'s front-and-center class.
9 Not Everyone Enjoys Mei's Overbearing Personality
Mei Hatsume from the Support Course is a driven, intelligent, and creative girl. She knows how to grab a crowd's attention, even without an ultra-fancy Quirk, and she thrives in the spotlight. She's even able to use a one-on-one Sports Festival match as a personal advertisement for herself and her inventions.
While it's true that a majority of fans find Mei's bold personality endearing, there's also a group of fans that find her to be too much. She's a blatantly selfish character who uses her intelligence and zany personality to attract attention, and not everyone is impressed by it.
8 Neito Rags On Class 1-A Without Proving Himself
Class 1-B is home to all manner of creative, intriguing characters – but Neito Monona isn't one of them. He's a side character with a self-confidence problem, which he masks by being as obnoxious as possible, badmouthing 1-A whenever he can to make himself feel better.
It's noted that he forces himself to do this, and it's only to push his classmates to perform better. However, the reasoning doesn't matter if it causes Neito to act in such an unbearable way that most viewers sigh in relief whenever Itsuka Kendo shows up to karate-chop him back into line.
7 Bakugo's Initial Personality Is Too Much To Handle
It's undoubtedly true that, over time, Bakugo blossoms into a fan-favorite character whose struggles hit incredibly close to home for many. However, there's also no denying that his early personality leaves much to be desired, and is hard for some fans to sit through.
Bakugo begins as an arrogant, cocky, loud-mouth character, who's constantly seen pushing others down, even if it's undeserved. This is true even for characters he considers a friend, like Midoriya, as he has no issue telling Izuku to "hope [he'll] be born with a Quirk in the next life, and take a swandive off the roof of the building" in the first episode.
6 Aoyama's Over-The-Top, Always-On Personality Is Exhausting
Out of all Class 1-A's members, Aoyama is by far the most dramatic. He also comes across as vein similarly to Neito, and acts like his Navel Laser Quirk is superior to that of his classmates, despite being one of the least-useful Quirks out of anyone in Class 1-A.
His Quirk has several obvious weaknesses – he can't use it for more than a single second at a time without causing himself harm, and he's completely defenseless if someone approaches him from the sides or behind. Despite this, Aoyama often talks himself up like he's far more powerful than he actually is, drawing the ire of both his classmates and the fanbase.
5 Inasa Harbors Intense, Undeserved Hatred Against Shoto
Inasa Yoarashi is a first-year student attending Shiketsu High School, and he possesses a fiery-hot, loud spirit. He's actually incredibly polite underneath this, but his hyperactive, forceful way of speaking can cause others in-universe to become irritated with him.
Believing that all heroes should be fiery, passionate people who place helping others above all else, Inasa grows to hate Endeavor immediately after meeting him due to his cold, hateful eyes. This hatred is then unfairly extended towards Shoto, simply for having the same eyes as his father, without considering the pain that Shoto's going through under him.
4 A Vocal Minority Believe Izuku Is An Over-Emotional Crybaby
At the beginning of the series, calling Izuku an overemotional crybaby is somewhat warranted.Understandably, he behaves this way due to incessant bullying from his pre-U.A. classmates, and a lack of belief in himself, but he retains this trait even after joining U.A.'s ranks and forming meaningful relationships.
The vast majority of fans understand that just because Izuku is a highly emotional character doesn't mean that it's a flaw, and adore all parts of him, even the side that's easily moved to tears. However, there is a small minority of fans who find this trait to be highly irritating, believing that it's not how a shonen protagonist should carry themselves.
3 It's Hard To Empathize With Kota's Point Of View
Kota is, essentially, a less compelling and understandable version of Inari from Naruto. Their initial personalities and actions are incredibly similar, but Kota fails to click with much of the fanbase early on, who view his personality and unwillingness to budge on his views irritating.
After the death of his parents at the hands of Muscular, Kota resents Hero society as a whole, but he's actually seen resenting his parents most of all. He's under the false belief that his parents abandoned him by choosing to work and die as Pro Heroes, and his attitude is hard to watch knowing that they only gave their lives fighting Muscular to keep Kota and other civilians safe from harm.
2 Some Fans Feel That Shinso's Move Into The Spotlight Is Undeserved
After the events of the Sports Festival, Hitoshi Shinso is one of the main Support Course students that remains etched into fans' minds. Seen to possess villainous powers by many, Shinso has to work incredibly hard to prove the good-natured value of his Brainwashing Quirk.
It's no doubt that Shinso becomes a fan-favorite, but there are others who believe that he shouldn't have been given the spotlight – at least, not yet. There are still quite a few members of Class 1-A that haven't been fleshed out satisfyingly, and it doesn't feel right to put so much focus on Shinso while others like Koda, Hagakure, Ojiro, and Shoji could still use it.
1 Mt. Lady Represents The Worst Of Hero Society
When the Hero Killer, Stain, refers to most modern-day heroes as false idols who are in it for all the wrong reasons, it's not as if this belief is entirely unfounded. After all, viewers are introduced to Mt. Lady in the first episode, who represents much of the issues people have with Hero society as a whole.
Mt. Lady loves the attention that being a hero gets her, which isn't difficult thanks to her size-enhancing Quirk, and she doesn't care if she wrongfully steals the spotlight from other heroes. She's also vain, using her charm to either boost her popularity for the wrong reasons or to gain free favors from others.