The definition of the word "canon" is the material that is officially recognized and accepted by the creator of the work as part of the main plot. It is generally written by the creator, respecting the main continuity of the series.
On the other hand, there is what is known as "non-canon" or "non-canonical", which includes elements that are not part of the official continuity of the series. These can be alternate stories, spin-offs, adaptations in other media, or even fanfiction.
It is important to note that the person who determines what is canon and what is not is the author of the work. For this reason, there are works that, even though the author had no participation in them, are considered "canon" because the author decided so, usually with prior evaluation to avoid continuity errors in the story.
Canon Classification in Anime
The "canon" in anime is divided depending on the material that was adapted, but this does not diminish the importance of the classification. Everything considered canon is important and relevant to the story.
Manga Canon
Episodes adapted from the manga are referred to as "manga canon". For years, the most popular manga in Japan have been adapted into anime to diversify profits and promote the manga itself, which is still being published.
Novel Canon
Episodes adapted from novels are referred to as "novel canon". In addition to manga, novels have become popular in recent years, including both web novels and light novels. This format suits authors better, as they only need to write one volume per year, unlike the weekly or monthly chapters of manga, which put a lot of pressure on many manga artists.
Anime Canon
Unlike the previous ones, "anime canon" is not adapted from manga or novels; the story was introduced directly in anime format, with supervision or some participation from the author. However, it is considered canon because the author determined it so. Examples:
- Episodes 50 and 51 of the One Piece anime are canonical despite not being adapted from the manga, this is because here it is explained how Ussop got his binoculars and Sanji the fish, in the manga it is only referenced in 2 vignettes.
- In Naruto Shippuden the movie The Last is canonical, this was announced in the publication of chapters 699 and 700 of the manga and was officially named chapter "699.5", which in the anime is between episodes 493 and 494.
- Hiro Mashima created the exclusive saga of the Key of the Starry Sky anime that covers episodes 125 to 150 of Fairy Tail, it is canonical, which although it does not follow the manga, the author determined it that way.
- In Boruto, much of the anime was not adapted from the manga, but that does not mean that it is filler, since the script and supervision is in charge of Ukyo Kodachi who is also in charge of the manga, in the anime he expands the main plot, deepening the history of characters that the manga could not.
Non-Canon
Unlike "anime canon", these episodes have no relevance to the story; they are simply created to buy time for the manga and unnecessarily extend the anime. These episodes are also called "fillers" because, as the name suggests, they serve to fill the plot without adding anything meaningful.