

Blue Reflection Ray is essentially a gentle anime, with romantic sentiments, but the visual aspects are rather crude, with simplistic character designs, and notably, the cast fails to capture the essence as portrayed in the original manga. In reality, Blue Reflection Ray has a promising storyline, but the filmmaking approach has ruined it all. Many fans are disappointed by the producer's carelessness.
The World Ends with You The Animation
The World Ends with You is an action role-playing game with urban fantasy elements developed by Square Enix and Jupiter for the Nintendo DS. Set in modern-day Shibuya shopping district of Tokyo, The World Ends with You boasts a distinctive art style inspired by Shibuya and youth culture.

When The World Ends with You was announced to become an anime, many fans felt excited and eagerly anticipated it, however, what they received turned out to be disappointing. The visuals, sound, and action scenes truly left gamers disappointed who had previously played the game.
Blade Runner: Black Lotus
Awakening without a name or memory, a young girl finds herself in a strange setting, that of Los Angeles 2032. After brief moments of recollection finally begin to restore in her mind, the young girl remembers her name is Elie and quickly realizes she is not an ordinary human. Recalling being hunted by strangers, Elie seeks out two strangers and embarks on a mission to reclaim her lost memories and to kill those who have attempted to kill her.

While intriguing in concept, the production studio was rather careless in trimming crucial parts of the storyline, creating discomfort for viewers. Hence, this anime faced much criticism and disappointment in its quality in 2021.
Humanity has grown weary after their nearly 30-year-long battle with the extraterrestrial beings known as BETA and began to believe that the end was near. In another twist, high school student Takeru Shirogane awakens and remembers seeing the future of humanity and how the plan to stop the BETA came to a failed end. In a desperate attempt to avert humanity's demise, Takeru tries to retrace his steps as he reengages with the soldiers fighting the BETA and revisits the failed plan called Plan IV.

Based on the novel series, Muv-Luv Alternative is not particularly captivating, with the production studio also overlooking many compelling aspects and attempting to condense the story into just 12 episodes. Audiences desired more from Muv-Luv Alternative and to this day truly feel that this anime adaptation is only mediocre at best.
Cestvs: The Roman Fighter
Cestvs, a slave warrior, seeks freedom from endless battles and constantly risks his life in every fight. Cestvs is told that if he can achieve 100 victories, he will be free, but can he attain such a feat? In the year 54 AD, individuals like Cestvs are tools for entertainment and when they can no longer perform, they are cast aside like sheep. Driven by the desire for freedom, Cestvs enters the arena of combat regardless of the high risk of death.

Cestvs: The Roman Fighter sounds like an extremely unique anime concept by using Rome as its backdrop. Unfortunately, this fighting anime was heavily cut in many important details. Not only is the animation stiff and outdated, but the story itself is also unappealing.
Ex-Arm
Akira Natsume, 16 years old, died after being hit by a truck in 2014. When Akira wakes up, he discovers that two major events have occurred. Now in the year 2030, Akira's body is no longer human. Akira's mind has been placed inside a special device called the EX-ARM, designed to assist a special police unit. The life Akira once knew has ended, but guided by his older brother, Akira knows he has a new mission in life that he must fulfill. Despite having a fairly promising storyline, the Ex-Arm anime version brings disappointing experiences to the audience and is listed as one of the anime disasters of 2021.

Above is the ranking table of the 7 most disappointing anime of 2021, the top name leaving many fans dismayed. Which name disappointed you the most? Please leave your opinions!