Right from the very start, Sword Art Online was a work of compromise. When Reki Kawahara first began writing the novel 20 years ago in the hopes of submitting it to the Dengeki Novel Prize, he struggled to make his ambitious concept fit the contest’s page limit. SAO was a story about escaping a death game VRMMORPG, but it was also a story about living life to the fullest inside the virtual world. To make these seemingly contradictory themes complement each other effectively, Kawahara set out to portray every facet of his world—the good, the bad, the thrills, and the downtime—but conveying all that within the scope of a one-shot was a tall ask indeed for a first-time author.
Eventually, Kawahara gave up on the competition and posted his manuscript online in the hopes that someone out there would find some enjoyment in it. Fortunately for him, his work attracted a modest following. SAO had all the telltale signs of a compressed book—it was filled with underdeveloped side characters and narrative threads—but it was by no means a bad story at its core. The positive feedback inspired Kawahara to keep writing, this time with the luxury of an unlimited word count.
This would be the beginning of Sword Art Online as a series that constantly revisits and reinvents itself. It’s the source of SAO‘s biggest storytelling flaws, but also its most interesting qualities.
Technically speaking, the story of “Sword Art Online” (the game) had already ended from the beginning. And although Kawahara did settle on a direction to take the series into the future, one of the first things he did was go back to the world of Aincrad and write side stories that take place within the gaps in the original story. The story of “Sword Art Online” might have ended, but there was still a lot of unfinished business for its characters and world.
There are obvious downsides to writing side stories after the fact. They can introduce inconsistencies with the original story (which, as Kawahara frankly admitted, has happened with SAO). More importantly, it can be difficult to justify their existence on a narrative level, because any original elements introduced in a side story can’t be allowed to influence the existing plot in an overt way. If that were to happen, it would become an “alternate universe” story rather than a matter of filling gaps in the original. For better or worse, attempts to refine an already-completed story draw attention to holes that ultimately weren’t relevant to the goals of the original work.
Nevertheless, SAO‘s side stories certainly are important to the overall plot because they introduce characters who become relevant in later arcs. The most significant example of this is Yui, who was introduced in a side story covering Kirito and Asuna’s honeymoon and comes back to play a major supporting role in the Fairy Dance arc. It’s a rather patchwork approach to storytelling, but it’s also one of the reasons behind the longevity of the series: By consistently referring back to events and characters from Aincrad, Kawahara ensures that the game of “Sword Art Online” never truly ends.
Adapting the series—first to print light novels and then to anime—gave the author yet more opportunities to reevaluate SAO from the beginning and add more to the story. He was faced with a choice: He could rewrite the Aincrad arc in a way that includes the later short stories as part of the original telling. Ultimately, however, he rejected that path because it would have involved far too much work. Instead, the early side stories were compiled into volume 2. A second Aincrad side story volume was released as volume 8, which included a new story about what Kirito did immediately after abandoning Klein on that fateful first day. The intent behind that volume was to represent the past and present of the series before diving into the print version of the Alicization arc, which was the original final arc of the web novel telling.
When it came to the anime, however, the production team decided on arranging the story in a chronological order. It might be relatively easier for a reader to adjust to a story that jumps around in time on a book-to-book level, but a TV show had to be more straightforward. It was under that logic that Kawahara was asked to write the events of episode 2 as a way of bridging the opening of SAO‘s main story to the side stories.
The results at the time were… mixed. Episode 2 tells the story of how the players conquered the game’s first floor; it ends with Kirito bearing the brunt of the players’ ill will and vowing to work alone. However, the next episode immediately opens with him joining a guild. It’s then revealed through the events of the episode that although his fellow guild members are low-level, Kirito is already a high-level player himself, indicating that the time gap between episodes 2 and 3 is even larger than you’d think at first glance. In other words, a bridging episode did not resolve the fundamental pacing problems caused by the time skip.
On the other hand, the experience of writing the plot of episode 2 was what gave Kawahara the motivation to actually sit down and “reboot” SAO on a more ambitious scale. The result is the Sword Art Online: Progressive light novel series, which includes an expanded version of the events of episode 2 and sets out to tell the story of how each floor was conquered in sequence.
Progressive is undoubtedly a fantastic novel series and one of the peaks of Sword Art Online as a whole. Because the first volume was published in 2012, a full decade after the original web novel started serialization, one could see it as the culmination of everything Kawahara learned as a writer. The more relaxed pacing allowed him to thoroughly explore the mechanics and social dynamics of the virtual world in detail, vividly bringing the world and characters of Aincrad to life like never before.
But Progressive isn’t necessarily consistent with the original story. The plot of episode 2 of the anime was originally written to establish the negative perception of Kirito as a “Beater” that lingers even in the later stages of the game, but in Progressive, the story moves on from the fallout. Not only do the other players soften their impression of Kirito within the course of the series, Kirito teams up with Asuna and goes on an extended series of adventures with her. So much for being a solo player, right?
The reason behind the inconsistencies is honestly quite understandable: An actually consistent telling would have involved volumes upon volumes of Kirito level-grinding and traveling alone, quickly devolving into tedium. Instead of defining him primarily as an overpowered lone wolf, Progressive‘s Kirito is frequently dragged outside his comfort zone to grapple with people problems too. Conflicts around side characters are necessary for building tension in a story where the ultimate outcome has been determined long ago.
Besides, bringing the story back to Aincrad gave Kawahara the opportunity to recalibrate the narrative around Kirito and Asuna’s courtship. The romance was always a big appeal of SAO, but in the original story, they went from distant acquaintances to lovers in record time. In Progressive, they have the opportunity to interact as friends and show a very different side of themselves to each other. It’s appealing to existing fans because they’re already familiar with the relationship dynamic.
In that sense, you could say that the retcons ended up building on the pre-existing narrative rather than outright replacing it. The anime continues with that tradition as well by incorporating the newer information into its adaptation. For example, a villain in the Alicization anime had his lines tweaked to make a passing reference to events from Progressive. There’s also the anime-original film Ordinal Scale, which was later referenced directly in the TV anime. The events of Ordinal Scale were also mentioned in the post-Alicization light novel volumes as a way of bringing the book and anime continuities together.
For fans who like to keep track of “canon,” these retcons might be a little infuriating. It’s easy enough to regard the video games separately because the game-original characters and scenarios never get referenced in the main story, but it’s still hard to say what the definitive version of SAO‘s story actually is. Personally, though, I don’t really mind. It’s a natural impulse for an author to want to keep refining their work, and I like how this approach keeps the story fresh yet still accessible in the long run. You can jump into the series from the first light novel volume or the anime and not lose anything, which is the most important thing.
The new Sword Art Online the Movie -Progressive- Aria of a Starless Night anime film represents yet another series of rewrites by introducing a new character and reframing the story around Asuna’s perspective. In terms of adaptation fidelity, it’s the most significant deviation the anime has introduced thus far, but when you take the long view about the series, it’s entirely within the spirit of things. I hope you can approach it with an open mind and try out the novels while you’re at it—it’s humbling to witness Reki Kawahara‘s growth as an author in real-time.