A strong manga or light novel does not always receive an anime adaptation capable of fully realizing its potential. Some series rush through major arcs, others move away from the source material, and many end before reaching a proper conclusion. Despite these shortcomings, they retain dedicated fanbases and stories that could benefit from modern animation and a renewed commitment to the original works.
D.Gray-Man is one of the clearest examples. The 2006 anime ran for 103 episodes and introduced Allen Walker, the Black Order, and their war against the Millennium Earl, but it stopped before the manga’s later developments. D.Gray-Man Hallow returned in 2016 with 13 episodes, though it covered only a small portion of the remaining story. A reboot could explore the intensifying conflict with the Noah family and the increasingly complex mythology surrounding Allen’s journey.
Katekyo Hitman Reborn! also ended without adapting the manga’s final arcs. Its 203-episode television run made it a notable 2000s shonen series, evolving from slapstick comedy into a story built around rivalries, tournaments, and elaborate battles. Tsuna Sawada’s growth from an awkward student into a capable mafia heir remains central to the series, while Reborn’s unusual training methods preserve its comedic identity. Since the manga provides a complete conclusion, a new anime could finally bring Tsuna’s story to its intended endpoint.
The World God Only Knows suffered from a different problem: its three seasons did not adapt the manga in a consistent order. The 2013 season moved directly into the Goddesses storyline, skipping intervening arcs and giving some heroines little introduction. Although OVAs restored parts of the missing material, major gaps remained. A reboot could follow Keima Katsuragi and Elsie’s journey chronologically, preserving the development of the romantic, supernatural, and dating-simulation elements that lead to the manga’s conclusion.
Soul Eater remains memorable for its eccentric cast, gothic setting, and supernatural threats. However, the 2008 adaptation eventually overtook Atsushi Ohkubo’s manga and adopted its own direction, including an anime-original finale. The manga continues through the Kishin’s return, the conflict with Asura, and the consequences of Crona’s choices. Those developments provide more definitive conclusions for characters such as Maka and Crona, making the series a strong candidate for a reboot faithful to the source.
Ouran High School Host Club is still regarded as a beloved shojo comedy more than two decades after its debut. Bones’ 2006 anime introduced Haruhi Fujioka and the wealthy members of the host club, but its 26 episodes covered only part of the manga. The adaptation also changed later material, leaving relationships and character arcs unresolved. The manga gives more attention to Haruhi’s feelings for Tamaki, his complicated family, and the relationship between Hikaru and Kaoru. A complete adaptation could explore the story well beyond the anime’s stopping point.
Black Cat’s anime also compressed and altered its source. The 2005 series adapted Kentaro Yabuki’s 20-volume manga in 23 episodes and created an original conclusion. That approach left less room for the Chronos organization, Creed Diskenth’s motivations, and the influence of Train Heartnet’s past on his decisions. The manga’s combination of gunplay, dark humor, supernatural elements, and character rivalries would have more room to develop in a new version.
Eyeshield 21 delivered an energetic shonen take on American football, following Sena Kobayakawa as his speed turns him into the Deimon Devil Bats’ secret weapon. The anime ran for 145 episodes but ended before the manga’s conclusion, leaving the team’s later achievements and the International Youth Cup unadapted. A reboot or continuation could complete Sena’s development and bring the full journey of the Deimon Devil Bats to the screen.
Great Teacher Onizuka remains known for its comedy and unconventional protagonist. The 1999 adaptation follows Eikichi Onizuka, a former biker gang member who becomes a high school teacher and attempts to reach students who challenge the school’s staff. Its 43 episodes cover only part of Tohru Fujisawa’s manga and alter several developments. A modern adaptation would also need to handle the story’s treatment of bullying, sexual harassment, abuse, and other difficult subjects carefully, while preserving the character-driven drama and rebellious humor that define the series.
Skip Beat! ends before Kyoko Mogami’s transformation into a serious actress can fully unfold. After discovering that childhood friend Sho Fuwa brought her to Tokyo mainly to act as his unpaid housekeeper, Kyoko enters the entertainment industry to get revenge. The 2008 anime covers only the opening portion of Yoshiki Nakamura’s long-running manga. Later arcs explore demanding performances, professional competition, and Kyoko’s increasingly complicated feelings involving Ren Tsuruga, leaving the anime without a conclusion to her career or relationships.
Negima!? never fully reflected the direction of Ken Akamatsu’s manga. The 2005 adaptation introduces young magician Negi Springfield and his class at Mahora Academy, but it arrived before the source reached its most ambitious material and eventually followed an original path. In the manga, Negi’s search for his missing father leads to the Magic World and a conflict involving Cosmo Entelecheia. The story also expands his training, friendships, and abilities. Although its extensive fan service could be controversial in a modern version, the later fantasy storyline provides a substantial reason to revisit the franchise.
Sources: Comic Book Resources.