Few things are more painful than seeing a beloved manga in anime form, only to discover the show fails to do the source material justice. It's also annoying to invest time in a bad or mediocre anime, then find out it was an excellent manga, but the full story spans hundreds of chapters. While good adaptations don't have to mirror their manga counterparts, they should retain the manga's merits and provide a coherent, enjoyable story.
Let's take a look at several of the worst manga adaptations ever made. Some, like My Little Monster, present romantic entanglements and vague hints at a backstory without a true resolution. Others, like Tokyo Ghoul √A, veer onto a different storyline, disregarding any of the elements making the manga great.
Tokyo Ghoul √A
The anime version of Tokyo Ghoul √A makes a bold choice, and many fans aren't happy about it. Instead of having Ken Kaneki continue to fight against Aogiri Tree as he does in the manga, the anime has him join them.
These major changes have interesting potential if executed well, but it's a risky decision the Tokyo Ghoul √A anime fails to warrant. Several plot points are completely nonsensical, resulting in a dramatic change in the tone of the series.
Unlike the first season where they took deep dives into the characters' minds, the anime's creators focused on random action sequences, which may occasionally seem senseless without knowing the drives behind them.
Gantz is an anime known for its jarring combination of gratuitous gore and slow-moving scenes seemingly serving no purpose; characters stand around for large chunks of time doing nothing. Also, the main character's perversion is not something everyone finds appealing.
The manga, on the other hand, is well-paced and has intricate characters. Kei Kurono, the protagonist, has more than the two or three traits he presents in the anime. Additionally, the manga properly resolves itself, explaining the mystery behind the Gantz spheres and its relation to the fate of the Earth.
The Deadman Wonderland anime started off great. The show depicts the horrifying world of the Deadman Wonderland prison, where vicious murderers compete in dangerous and degrading games for onlookers' amusement. On a class field trip, the main character's peers die; he shoulders the blame for their demise. His sentence is death row at the prison.
From there, things start to go downhill. Rather than thrilling the audience with fresh horrors, as the manga does, this anime devolves into increasingly meaningless action sequences before ending with little to no resolution.
Natsuki Takaya's Fruits Basket is an intricate family drama focusing on the Sohma family, an isolated group with a curse transforming them into Chinese zodiac animals. More than their curse, this family suffers from rampant child abuse, secrecy, and other ills. When Tohru Honda appears in their lives, the painful nature of their family life begins to change.
The anime version of Fruits Basket gets the basic premise across, but it leaves out almost 80% of the story. Major characters don't appear, there are unexplored mechanisms behind the curse, and few conflicts have resolutions. It's an okay anime on its own, but when compared to the manga, it falls apart.