The anime industry has produced timeless favorites, but many once-popular series have gradually lost their status or faded from fans’ memories. Whether due to long gaps between seasons, declining quality, or controversial changes from the original source, these once-hit anime failed to recapture their former glory.
10. Hetalia: Axis Powers
While newer anime fans might not be familiar with it, nearly two decades ago Hetalia: Axis Powers was a phenomenon. The series personified countries as humorous male characters based on cultural stereotypes. With seven seasons, a movie, and many specials, Hetalia built a loyal fanbase. However, its popularity has steadily declined over the years.
9. Blue Exorcist
Blue Exorcist peaked in 2011 with its first season, becoming one of the most beloved shounen series. However, due to insufficient manga content, the anime created an original ending that sparked controversy. Although a follow-up season aired in 2017, the six-year gap and skipping the end of season one made it difficult for both longtime fans and newcomers. The studio change from A-1 Pictures to Studio VOLN also led to a drop in quality, causing the series to lose much of its audience compared to its heyday.
8. The Rising of the Shield Hero
The Rising of the Shield Hero was once hailed as one of the best isekai anime thanks to its unique story. However, season two disappointed many with the Spirit Turtle arc, considered one of the weakest parts of the series. Although later arcs improved, the show gained a negative reputation and lost much of the initial excitement and attention.
7. Log Horizon
Log Horizon quickly became a popular isekai thanks to its MMORPG setting and deep storyline. But starting with season two, after moving to Studio Deen, the animation and story quality declined. Although season three was better received, a six-year gap caused by the author’s legal issues diminished the series’ appeal.
6. The Devil is a Part-Timer!
The Devil is a Part-Timer! was once a beloved reverse isekai comedy. However, its follow-up season, released nearly a decade later, disappointed fans. The studio switch from White Fox to 3Hz led to a drop in animation quality and art style. Additionally, the story shifted focus to a new character, Alas Ramus, losing much of the original humor and causing many viewers to drop the series.
5. Tokyo Ghoul
Despite some animation flaws, Tokyo Ghoul attracted viewers with its dark story and deep exploration of human nature. However, Studio Pierrot damaged the series by straying from the manga in season two. The follow-up Tokyo Ghoul:re crammed too many manga chapters into just two parts, making the plot confusing. Although fans have called for a remake, Tokyo Ghoul has yet to regain its original standing.
4. The Melancholy of Haruhi Suzumiya
This anime was hugely popular in 2009 until it took a risky move: airing the same episode eight times over two months. This “Endless Eight” arc was meant to convey the characters’ feeling of being trapped in a time loop. However, this backfired, causing Haruhi Suzumiya to lose many fans and the chance for a third season.
3. Seven Deadly Sins
Seven Deadly Sins was once a unique fantasy adventure anime that quickly won fans. But its downfall began after switching to Studio Deen. The animation quality plummeted, ruining one of the most anticipated battles. This inconsistency continued in later seasons, pushing many fans to turn to the manga instead.
2. Tokyo Revengers
The first season of Tokyo Revengers exploded in popularity with its mix of time travel and gang conflicts. However, the manga later faced criticism for declining plot quality, and its disappointing ending affected the anime. Subsequent seasons suffered from animation issues and were criticized for lacking character development for protagonist Takemichi, causing the series to lose much of its original audience.
1. The Promised Neverland
The first season of The Promised Neverland was a massive success, but season two turned into a disaster. To rush the ending, the anime production team cut many key details, including a famous story arc and beloved characters. With excessive censorship, the plot became disjointed, making season two one of the worst in anime history and permanently damaging the series’ reputation.