There have been some truly great characters throughout the history of anime, including Spike Spiegel, Edward Elric, and Sailor Moon. Viewers latch onto these characters and their stories to see how they grow and change throughout their respective series. For the iconic characters in anime, their arcs truly make them memorable. Even if there are some stumbling blocks, the experience is positive overall.
Unfortunately, there are instances where a perfectly good character is utterly ruined in the eyes of the audience. Whether due to bad behavior, baffling choices by the writers, or just running out of goodwill from viewers, some characters change from favorites to more problematic figures with a single scene.
Rachel - Tower of God
Tower of God follows Twenty-Fifth Bam, a boy who spent his life trapped beneath the mysterious Tower with only his best friend Rachel for company. When Rachel enters the Tower, Bam goes after her out of love. Over the course of 12 of the 13 episodes in the anime series, audiences get invested in the deep bond that Rachel and Bam have with each other.
At the end of Tower of God episode 12, Rachel pushes Bam over the edge of a platform in a flat-out murder attempt. Not only does this betrayal come out of nowhere, but it's also revealed that Rachel has always been secretly jealous of Bam this whole time. It's a shock for both Bam and viewers in an unpleasant way, even with the clarification in the following episode.
Shigure Sohma - Fruits Basket
Fruits Basket follows Tohru Honda as she finds herself involved with the mysterious cursed Sohma family, whose members can turn into Chinese Zodiac animals when touched by the opposite sex. A deceptively cute shojo story at first, both the manga and the anime grapple with some fairly dark themes. One character that embodies this deception is the Dog of the Zodiac, Shigure, who manipulates everyone in the series to get what he wants, specifically Akito.
While he plays up an affable demeanor, one scene, in particular, is truly unnerving where he speaks with Tohru about the nature of the Zodiac Curse. While it's a moment of frustration on his part, the fact Tohru didn't do anything to be spoken to that way just ends up souring the character.
Katsuki Bakugo - My Hero Academia
Bakugo, arguably one of the co-leads of My Hero Academia, remains a pretty divisive figure amongst viewers of the anime. While the character does grow into a more caring person as the series progresses, there's a key moment early on that ruins him for many.
The scene in question is infamous amongst My Hero Academia viewers, where Bakugou tells Izuku Midoriya, the protagonist, to "Go take a swan dive off the roof!" in order for the Quirkless character to get a Quirk in the next life. While Bakugou is often a bully to Midoriya. there's a line between bullying and telling someone to harm themselves.
Kenshin Himura & Kaoru Kamiya - Rurouni Kenshin: Reflection
For audiences of Rurouni Kenshin, there is some debate if the OVAs made after the original series are considered canon, especially Rurouni Kenshin: Reflection. There are a lot of not-great moments within the OVA, but one kind of ruins the characters of both Kenshin and Kaoru is one go. In it, Kenshin wanders from time to time in order to atone for his past actions but comes home with an unknown disease.
Kaoru asks him to have intercourse with her so that she may be infected by this unknown disease and can share in his pain. Then, they both have intercourse for this to happen exactly as Kaoru intends.
Maes Hughes - Fullmetal Alchemist
In Fullmetal Alchemist, the death of beloved figure Maes Hughes is one of the most tragic moments. Hughes is a devoted friend, great at his job, and one of the most doting fathers in the history of anime. Due to his unfortunate death, it's hard to enjoy the character knowing how his story will ultimately end.
While there's nothing wrong with the character himself, Hughes is an example of how a sad end can retroactively ruin the character in rewatches for audiences.
Anthy Himemiya - Revolutionary Girl Utena
In the world of Revolutionary Girl Utena, duelists fight in a tournament to win the Rose Bride, Anthy Himemiya, for the power to change the world. During the series, however, the dark secrets of Anthy and her brother Akio come to light, yet Utena still fights for Anthy's sake. The bond between both Utena and Anthy only grows deeper as time and the series progresses for the pair.
In the final duel between Utena and Akio, Anthy ends up stabbing Utena in the back. She suddenly reveals her darker purpose and nature, ruining one of the best relationships in anime.
Son Goku - Dragon Ball GT
The whole Dragon Ball franchise is full of plot twists, weird moments, and excellent fight scenes. Out of the entirety of Dragon Ball, which boasts many anime series, manga, and films to its name, the worst entry for audiences (outside of the live-action Hollywood version) is Dragon Ball GT.
This is exemplified by Goku age regressing back into a child, which ends up feeling like a big step back for the character overall.
Inuyasha - Inuyasha
The will they/won't they tension between Inuyasha and Kagome is at the core of the long-running anime series Inuyasha. Unfortunately, Inuyasha is still hung up on his ex, Kikyo. Not only is Kagome the reincarnation of Kikyo, but Kikyo also gets resurrected at one point. Inuyasha also tends to lose all sense in regards to Kikyo, even when she has turned to the dark side after her resurrection.
At multiple points in the series, Inuyasha goes to Kikyo, despite things with Kagome getting a little bit romantic. While it's drama for the story, it also comes across like Inuyasha prefers one over the other in a very clear way.
Chibiusa - Sailor Moon
In Sailor Moon, Chibiusa is the future daughter of Usagi and Mamoru, who comes to the past in order to save the future. While her relationship with Usagi, who is Neo-Queen Serenity in the future, is rather fraught, the opposite is true with her father. There is an old saying that suggests every girl's first love is there, but Chibiusa takes it to a disturbing level, especially in regards to Black Lady.
When Chibiusa becomes this older and evil version of herself, she brainwashes Mamoru, and the two nearly kiss. The fact Chibiusa does this to the younger version of her father adds a new amount of ick to the whole proceeding.
Homura Akemi - Puella Magi Madoka Magica: The Movie Part III
Puella Magi Madoka Magica is one of the best magical girl animes out there. Not only is it an interesting deconstruction and subversion of the magical girl trope and story, but the anime focuses on the themes of sacrifice, grief, and hope. Madoka becomes a goddess in order to help protect magical girls. While it's terrible for those who loved her, it still leaves a powerful message.
Then, the movie happens. In it, Homura, a magical girl who lives many different timelines in order to save Madoka, turns into the Devil as part of her psychotic and possessive love for her friend. It undermines basically everything that made the original series compelling and bittersweet, especially for the character herself.