The anime industry has gained a solid presence worldwide, with numerous series achieving massive popularity and remaining highly recommended despite the passage of time, only gaining more and more followers, and enjoying widespread recognition. However, some anime that were once incredibly popular gradually fall from their mainstream status or lose huge parts of their fan base.

Whether it’s due to the sheer number of series premiering each season, the lack of new content, a large gap between seasons that causes fans to lose interest and focus on other options, or a decline in its quality, some hit anime that were once considered gems get lost in time and the memory of the viewers.

Hetalia: Axis Power

While the new generation of anime fans may not have heard much about Hetalia: Axis Powers, it reached great notoriety almost two decades ago. Hetalia was a quirky, bizarre anime that anthropomorphized countries into exaggerated, caricatured male versions based on stereotypes of their cultures. Hetalia was a massive franchise, with seven seasons, a movie, video games, and numerous special episodes.

Hetalia: Axis Powers has a humorous tone, using satire to reference historical events, and has gained a loyal fan base thanks to the unusual way it portrays political relationships between countries through their interactions. However, while Hetalia was not without controversy, the series’ popularity remained strong for several years until it gradually declined.

Blue Exorcist

During its first season in 2011, Blue Exorcist reached its peak popularity in Japan thanks to the success of the manga, becoming one of the most recommended series by shōnen fans in the West. However, since the manga didn’t have much content at the time, the anime created an original ending that received mixed reception.

While Blue Exorcist was renewed in 2017, the discrepancies with the source material, the 6-year gap, the manga being monthly, and the fact that viewers needed to skip the last episodes of season 1 affected interest in the franchise from old fans and created a barrier for newcomers.

Although the Blue Exorcist anime continued and is expected to release a fourth season, proving that the franchise still has a loyal fanbase, it also experienced a drop in quality following the change from A-1 Pictures to Studio VOLN. This contributed to Blue Exorcist having a much smaller audience compared to its glory days.

The Rising of the Shield Hero

The Rising of the Shield Hero was hyped as one of the best isekai anime during its first season, thanks to the unique power given to the protagonist, Naofumi, and how fascinating his journey felt to fans, since he wasn’t the typical hero, being aware of others after being wrongly accused and mistreated.

Sadly, many viewers decided to drop the anime after the release of The Rising of the Shield Hero Season 2 due to the Spirit Turtle Arc being considered one of the weakest of the story. While the following anime installments had an improvement in narrative quality, The Rising of the Shield Hero gained a bad reputation and no longer enjoys the same hype.

Log Horizon

Log Horizon quickly became one of the most recognized isekai anime thanks to its MMO dynamic, which led many fans to compare it to Sword Art Online. Furthermore, Log Horizon‘s detailed world-building and political undertones received praise from the audience. Given that Log Horizon Season 2 switched studios to Studio Deen, it experienced a slight drop in quality.

Although the anime’s narrative also declined compared to the first season, fans hoped it would improve in the third. However, although the third season was considered better than the second, it took six years to release, likely due to the controversy surrounding Log Horizon‘s author, Mamare Touno, who was charged with tax evasion in 2016.

As a result, Log Horizon lost popularity due to the considerable gap between releases, and many were disappointed by the story’s deterioration compared to what attracted viewers in the first season. This, coupled with the fact that the Log Horizon light novel has been on hiatus since 2018, caused audiences to increasingly lose interest in the franchise.

The Devil is a Part-Timer!

The Devil is a Part-Timer! earned a good reputation as one of the best and funniest reverse isekai, but it was hindered due to its disappointing sequel. The Devil is a Part-Timer! season 2 was released almost a decade later and failed to revive interest in the franchise due to the change of studio from White Fox to 3Hz.

The Devil Is a Part-Timer! season 2 featured a downgrade compared to the original art style and animation, as well as significantly less comedy by focusing on Alas Ramus. These changes weren’t well-received by many viewers, and the ending of the original light novel also sparked backlash, which didn’t help The Devil Is a Part-Timer‘s popularity.

Tokyo Ghoul

Custom Image by Ana Nieves

Despite having some animation flaws and censorship, Tokyo Ghoul captivated fans. Tokyo Ghoul became one of the most popular dark fantasy anime in 2014 thanks to its astonishing exploration of human nature through Kaneki, who experiences a drastic personality change due to the trauma he faces. However, Tokyo Ghoul‘s adaptation by Studio Pierrot squandered the story’s potential.

The sequel deviated from the manga with the following installment, Tokyo Ghoul: Re, cramming too many chapters into a two-cour season. The disappointing adaptation made many viewers avoid the anime entirely, causing it to lose popularity. Yet, many fans decided to switch to the manga and continue clamoring for Tokyo Ghoul to get a remake.

The Melancholy of Haruhi Suzumiya

The Melancholy of Haruhi Suzumiya was extremely popular in 2009, until its controversial story arc, known as “Endless Eight.” The anime experimented with viewers by airing the same episode eight times over the course of two months. By repeating the same scenes with minimal variations, the anime aimed to convey the experience of the characters trapped in a time loop.

However, “Endless Eight” was a risky move that backfired on the anime. Many fans felt cheated, and The Melancholy of Haruhi Suzumiya not only lost many fans but also the possibility of being renewed for a third season. While the anime is still relevant, and later released The Disappearance of Nagato Yuki-chan in 2015, it never recovered its former popularity.

Seven Deadly Sins

The Seven Deadly Sins presented a unique magical adventure in a medieval world that, despite being influenced by Arthurian legends, had its own touch, quickly rising as one of the most hyped anime at the moment and gaining fans around the world. However, The Seven Deadly Sins‘ downfall began with its switch to Studio Deen.

The Seven Deadly Sins experienced an infamous drop in animation quality that ruined one of the most anticipated battles by fans. The anime continued to have inconsistent animation, something that has also permeated its sequel. Although the franchise continues to be well-known, many fans decided to drop The Seven Deadly Sins anime and continue the story in the manga.

Tokyo Revengers

After the premiere of its first season, Tokyo Revengers had a boost in popularity due to its intriguing mix of delinquents, time travel, and mysteries, becoming the third best-selling manga during 2021. However, the story went downhill, and the poor reception of the manga’s ending cast a shadow on Tokyo Revengers‘ anime.

The subsequent seasons of Tokyo Revengers suffered from animation flaws, failing to convey the manga’s art in motion, and were criticized because many viewers expected more character development for Takemichi as the protagonist. Although Tokyo Revengers is expected to premiere a fourth season, the anime has lost much of its initial audience.

The Promised Neverland

The Promised Neverland had a successful first season, which covered the Jailbreak arc, considered one of the best in modern shōnen. However, the manga’s lackluster ending prompted the anime production team to make changes for The Promised Neverland‘s second season, removing some of the series’ best elements, including important characters and a highly anticipated story arc.

These changes and the excessive censorship made The Promised Neverland‘s story lose its impact and be remembered as one of the worst second seasons of anime in history. While The Promised Neverland continues to receive praise for its first season, its overall reputation has been tarnished forever.