When manga get adapted into anime, viewers almost always dread the existence of filler episodes. After all, when an anime catches up too soon with its manga origins, there won't be any "new" content to adapt. Sadly, the existence of rather dull filler arcs did give these episodes a bad reputation among anime fans.
However, some filler arcs do tend to impress fans, so much so that it's regrettable they're not part of the official canon. Some filler arcs become so stellar that they serve as must-watch parts of any anime experience, like those below.
Updated November 29, 2021 by Rei Penber: Ten of the most phenomenal filler arcs in anime have already made the list; however, there are many anime out there with incredibly rich stories. The potential to add to a massive story to these worlds been fully explored by the respective studios by adding many incredible filler arcs. These arcs are filled with likable characters and have gripping stories which is why the fans should give them a shot. With that in mind, we've included four more arcs of the same caliber and elaborated on the existing list, providing readers with more to add to their watch list.
14 One Piece: Warship Island Arc
One Piece is an ongoing series that recently reached a milestone of 1000 episodes, which just goes to show that the potential for fillers in this story is massive. In between the story-driven and action-packed arcs are some filler arcs that fans sadly often skip, because they aren't connected to the main plot. Among the many incredible filler arcs in the story, the Warship Island arc certainly stands out.
The first filler arc of One Piece, this one runs from episode 54 to episode 61. Viewers follow the beloved Straw Hat Pirates who help a child named Apis, who wants to assist his dragon friend, Sennenryu, in reaching his home safely. This is easier said than done, however, as the Marines are on their tail to capture this mythical creature for their own benefit.
13 Naruto: Itachi Shinden Book: Light and Darkness
The Naruto series is no stranger to filler arcs, as about half of the anime is filled with it. As such, it is no surprise that this anime has more than just one decent filler arc. This particular arc is focused on Itachi's life. Itachi Shinden Book: Light and Darkness is a fan-favorite arc, beginning with episode 451 ending with episode 458. The arc follows a young Itachi and fans watch him grow up, witnessing everything that makes him the shinobi we all know to be.
What makes this arc special is the focus that it throws on Shisui. His relationship with Itachi is fleshed out as well. This arc has that powerful narrative that Naruto is known for, as well as some beautifully animated fight sequences that make each episode an incredible experience.
12 Hunter x Hunter: Zoldyck Family Arc
The Zoldyck Family arc takes place right after the Hunter Exams arc, and is one of the few unofficial arcs in the Hunter x Hunter series. This arc follows Gon, Kurapika, and Leorio as they make their way to Kukuroo Mountain, where Killua lives, to help him. Fans get introduced to the Zoldyck family, which includes Killua's father Silva Zoldyck, his mother Kikyo Zoldyck, and his grandfather Zeno Zoldyck, among others.
Although just five episodes long, this arc focuses deeply on Killua's character. At the same time, it isn't heavy in terms of action. Nonetheless, the arc certainly adds another layer of depth to the fan-favorite characters and sets up interesting things for the future.
11 Boruto: Mitsuki's Disappearance Arc
After the end of the Naruto series, Boruto rose as its successor. With the new generation taking the spotlight, fans see the likes of Boruto, Sarada, and Mitsuki on their adventures. This arc, in particular, focuses on Mitsuki, the son of the legendary Orochimaru. Although already a compelling character by this point, this arc focus on his character even more.
The arc sees Mitsuki get caught in an inner conflict, which ultimately leads to him leaving his village in order to better understand himself as a person. Expectedly, his friends start to pursue him to bring him back where he belongs, much like Naruto did with Sasuke in the past.
10 Bleach: Reigai Uprising
Fans of Bleach love the series' unique take on various concepts related to spirituality and the supernatural, and the Reigai Uprising Arc takes this to the next level. This filler arc explores the Modified Souls, artificial souls that can enhance human bodies to help them fight Hollows. In a mysterious series of events, Mod-Souls have begun an uprising in which they "replaced" various Soul Reapers.
This arc unleashes a wild take on the "body snatchers" concept from sci-fi stories. While fans know Ichigo will somehow find a way to resolve the issue, viewers may find this exploration of the Mod-Souls a welcome expansion into the concepts introduced in the series.
9 Naruto: Three-Tails' Appearance
Prior to the Fourth Great Ninja War, the Akatsuki initially wanted to capture and seal all Tailed Beasts. A part of this process required sealing the Three-Tails, which takes the form of a giant turtle. In the Naruto manga, Akatsuki members Deidara and Tobi captured the beast with little resistance, whereas the anime devoted a 23-episode filler arc to this struggle.
A team working for Orochimaru actually fights an entire three-squad regimen from Konoha for control over the Three-Tails in this arc. Fans meet Yukimaru, a boy who can partially control the Three-Tails, as the central figure of conflict in the story.
8 Dragon Ball Z: Other World Saga
After the events of the Cell Saga, Dragon Ball Z shows Gohan grow into a studious teenager about to enter high school in the Great Saiyaman Saga. Sadly, Cell's demise led to a world without Goku, though everyone knows he's having a fun time in heaven. The Other World Saga explores such an occurrence with the reveal that Goku has stumbled upon another tournament, this time among other deceased champions.
This four-episode filler elaborates on Goku's participation in the Other World Tournament. In the anime, whoever won the tournament receives training from Grand Kai, the person in control of all quadrants of the galaxy.
7 Haruhi Suzumiya: Endless Eight
Granted, the Endless Eight Arc in the anime adapts the Endless Eight short story from the novella. The two stories also have the same premise, in which Kyon and the gang experience a time loop of the events between August 17 to August 31. Whereas the short story is, well, short, the anime takes this into extreme heights. The Endless Eight arc is stretched into eight episodes.
Viewers at the time needed to patiently watch through the eight episodes of similar content, with minor differences in its events. While some detractors claim the arc is "boring," fans of the franchise will appreciate the significant differences of the Endless Eight filler from the original short story.
6 One Piece: G-8 Arc
As mentioned above, One Piece definitely has a few filler arcs — and many of them are worth watching. Interestingly, the G-8 Arc is the longest filler arc in the series, with only 11 episodes. This takes place after the Straw Hats left Skypiea (Sky Island Saga), where they sail near heavily-fortified marine waters instead of the open sea.
Throughout this arc, Luffy and his friends scatter and try to make their way back to the Going Merry. As expected, their covers all hilariously get blown. Despite this filler arc becoming a bit predictable, it serves as a great way to flesh out the personalities of the Straw Hats. It also served as a source of their strong bonds throughout the rest of the series.
5 Sailor Moon: Makai Tree Arc
Fans of Sailor Moon would appreciate the many adventures of Usagi Tsukino (Sailor Moon) and her Sailor Senshi friends as they save the world. However, their stories in the anime would also receive their own filler arcs. Interestingly, fans hold Sailor Moon's Makai Tree Arc in high regard, referring to it as one of the best filler arcs to ever grace anime.
In it, the extraterrestrial Makai Tree arrives on Earth in need of love for sustenance. As such, its children An and Ail tried to forcibly take human energy to do this. To save Earth's citizens, Sailor Moon and the Sailor Senshi will have to stop the Makai Tree's children, with this arc providing some of the best character development in the series.
4 Yu-Gi-Oh!: Waking The Dragons
Of all Yu-Gi-Oh! Duel Monsters filler arcs, its "Orichalcos" arc – dubbed Waking The Dragons – displays the most impact with its narrative and character growth. In this arc, a mysterious organization known as Doma has started using the Seal of Orichalcos to steal people's souls. Yugi and his friends need to discover an untapped power to stop Doma once and for all.
Interestingly, this arc bridges perfectly into Pharaoh's Memories. It provides much-needed character development before fans finally get to uncover the Pharaoh's past.
3 Bleach: Zanpakuto Rebellion
In Bleach, Soul Reapers rely on Zanpakuto – weapons imbued with a warrior spirit – to fight supernatural opponents. A Soul Reaper in tune with their Zanpakuto can unleash their Bankai, their fullest potential. However, in this arc, a rogue Zanpakuto named Muramasa sets other spirits apart from their lieges, amassing a Zanpakuto Rebellion in Soul Society. Even the Gotei 13 lost control over their cherished partners.
Being a filler arc, fans know that Ichigo Kurosaki will defeat Muramasa and save the day. However, it's still interesting to see interactions between Shinigami and their respective Zanpakuto. They often give insights to the nature of their unexplored partnerships.
2 Saint Seiya: Asgard Arc
Saint Seiya's Asgard Arc has a unique history. Its events first appeared in The Heated Battle Of The Gods, the second anime film in the franchise. However, the events in the anime stray from the film. The Asgard Arc has its own unique Norse-themed story that ties in perfectly with the anime's next arc.
The Bronze Knights – the most novice of Athena's chosen champions – have to save her from Hilda and her cronies. While the arc has its staple set of battles, the story does offer villains with compelling backstories, as well as a satisfying ending.
1 Naruto: Kakashi's Anbu Arc
Kakashi Hatake isn't just notable for his mastery of the Sharingan. Rather, the prodigious Kakashi earned the title of the best in his generation. It's no wonder he became shuffled into the ranks of the Anbu. Any Naruto fan would wonder just how far "in the black" Anbu missions go would go, and Kakashi's Anbu Arc showed just that.
This arc occurs in Naruto Shippuden, during the Fourth Great Ninja War. Despite its odd timing, this filler arc does a good job of expanding the backstories of numerous characters and events. These include giving better backgrounds Itachi Uchiha and Yamato, as well as insights towards the Uchiha Clan Massacre and even Kakashi's emergence as the jonin leader of Team 7.