As a long-running shonen, the One Piece anime adaptation has always strived to stay faithful to the source material. And in hindsight, it managed to stay honest without straying too much from the manga. And even if it did branch out for a bit, it eventually rerouted to the correct path--though the occasional fillers and horrendously slow pacing make it appear as otherwise.
But even while staying faithful to the manga, the anime adaptation still chooses to omit some canon that would otherwise provide important pieces of information: cover page stories. These mini-series cover various side stories that are interlinked with the overall plot. They are entirely canon, which means that whatever event ensues there holds a certain extent of relevance to the story. Some of them have gotten slight coverage in the anime, while the rest stayed manga-exclusive for the most part.
10 "Gang" Bege's Oh My Family
This mini-arc follows the adventures and misadventures of the Capone family subsequent to the events of Whole Cake Island Arc. After getting information about Lola from Nami, Chiffon convinces her husband to set out and look for her missing twin sister.
The arc eventually concludes with the sisters’ joyful reunion and Lola’s wedding. Moreso, Pound, their father, somehow escapes from Totto Land and gets a piece of the tearful reunion.
9 Solo Journey Of Jinbe, Knight Of The Sea
There are multiple pieces missing from Jinbe’s own saga. While the anime showcases all vital information regarding Jinbe, the manga tries to fill in the blanks as much as possible; hence, this mini cover story.
Jinbe’s solo journey takes place post-Fishman Island Arc. Most of the journey centers around Jinbe aiding a lost sea kitten and interacting with various sea beasts.
8 Miss Goldenweek's "Operation: Meet Baroque Works"
Following the events of Alabasta and the fall of Crocodile’s Baroque Works, Miss Goldenweek devises a plan to rescue her imprisoned comrades with the help of Mr.5 and Miss Valentine.
This short story is one of the earliest cover stories as well as one of the longest. Over the course of 42 manga chapters, the oddly satisfying dynamics of the Baroque Works is laid barren for the fans to enjoy.
7 From The Decks Of The World
Two years after the War of the Best, the Straw Hats make their second debut; this time aiming for a much wider sea to explore and more formidable challenges to conquer. Their comeback, of course, garnered all sorts of reactions from their acquaintances and enemies alike.
From the Decks of the World highlights the various reactions of fan-favorite characters who stayed off the screens for hundreds of chapters including Vivi and Crocus.
6 From The Decks Of The World: The 500,000,000 Man Arc
The second installment of From the Decks of the World features the various reactions of the same characters starring in the first part of the mini-series and more. The first part kicked off immediately after the timeskip, whilst this part commenced after the fall of Doflamingo.
Some notable faces in this part include Monkey D. Dragon and the Red Hair Pirates. Makino and the residents of Fusha Village also got some screentime.
5 Hatchan's Sea-Floor Stroll
Arlong and his gang of fish-men ruffians were stopped once and for all by the Straw Hats. Their dethroning in East Blue was followed by the Marines getting a hold of and transferring them to the place where they truly belong--prison.
By a dumb stroke of luck, Hatchan escaped imprisonment and embarked on a journey of self-exploration. Camie and Pappag make their initial debut in this mini-story, over 100 chapters earlier than their official introduction in the anime.
4 The Stories Of The Self-Proclaimed Straw Hat Grand Fleet
The Stories of the Self-Proclaimed Straw Hat Grand Fleet sheds light on the individual journeys of the core members of the Straw Hat Grand Fleet after their separation in Dressrosa. The mini-series offers a unique outlook on the lives and antics of the followers of Luffy.
Bartolomeo visits an island, sells Straw Hats merch, and daringly burns the flag of the Red Hair Pirates--a crazy act even by his own standards. The rest of the team’s journeys are just as exciting, if not more.
3 Enel's Great Space Operations
Oftentimes the One Piece canon intrudes into some bizarre boundaries that make one question its authenticity. The pushed boundaries blur the defining line between fillers and canon--effectively rendering the fans confused.
Enel’s Great Space Operations is such a story; it features the moon, an ancient civilization, and actual aliens--all of which are 100% canon. It is a very interesting ride, to say the least.
2 Ace's Great Blackbeard Search
The late Ace’s search for Blackbeard lasted only a handful of minutes worth of screentime in the anime. In the manga, however, an entire mini-arc was dedicated to the search.
The cover series comprised 29 cover pages with each picture telling a thousand words. If the mini-arc was to be adapted to the anime, then most fans would unhesitantly flock to it.
1 CP9’s Independent Report
Most fans assumed Rob Lucci and the team met their maker after the buster call on Enies Lobby. After all, the anime offered no follow-ups regarding the CP9 whatsoever. It’s only natural that fans would be skeptical.
This story highlights a side to the CP9 previously unknown to the fans. Most of it takes place on a relatively peaceful island where the CP9 focuses on healing and planning for the next big move.