<p>Based on a google search for <a href="https://www.google.com/search?q=site%3Amyanimelist.net+%22episode+0%22" rel="nofollow"><code>site:myanimelist.net "episode 0"</code></a>, we find the following episodes:</p>

<ul>
<li><a href="http://myanimelist.net/anime/3456/Candy%E2%98%86Boy_Episode_0" rel="nofollow">Candy Boy Episode 0</a> (a pilot, airing 6 months before <a href="http://myanimelist.net/anime/4535/Candy%E2%98%86Boy" rel="nofollow">Candy Boy</a>)</li>
<li><a href="http://myanimelist.net/anime/8857" rel="nofollow">Nichijou Episode 0</a> (a pilot, airing a month before <a href="http://myanimelist.net/anime/10165/Nichijou" rel="nofollow">Nichijou</a>)</li>
<li><a href="http://myanimelist.net/anime/10897/Boku_wa_Tomodachi_ga_Sukunai_Episode_0" rel="nofollow">Haganai Episode 0</a> (a pilot, airing a few weeks before <a href="http://myanimelist.net/anime/10719/Boku_wa_Tomodachi_ga_Sukunai" rel="nofollow">Haganai</a>)</li>
<li><a href="http://myanimelist.net/anime/8740/One_Piece%3a_Strong_World_Episode_0" rel="nofollow">One Piece: Strong World Episode 0</a> (a prequel to <a href="http://myanimelist.net/anime/4155/One_Piece%3a_Strong_World" rel="nofollow">One Piece: Strong World</a>)</li>
<li><a href="http://myanimelist.net/anime/2346/Ichi_The_Killer%3a_Episode_0" rel="nofollow">Koroshiya 1: Episode 0</a> (not sure about this one - Japanese Wikipedia says that it's about Ichi's past, so I guess it's a prequel?)</li>
<li><a href="http://myanimelist.net/anime/2346/Ichi_The_Killer%3a_Episode_0" rel="nofollow">Hakuouki Hekketsuroku Episode 0</a> (a recap of the first season, and hence a sort of "prequel" to <a href="http://myanimelist.net/anime/9065/Hakuouki_Hekketsuroku" rel="nofollow">the second season</a>, which aired a week later)</li>
<li><a href="http://myanimelist.net/anime/4156/Ichigo_Mashimaro_Episode_0" rel="nofollow">Ichigo Mashimaro Episode 0</a> (not sure about this one; it may be worth noting that it's called "Prologue" rather than "Episode 0" in Japanese)</li>
<li><a href="http://myanimelist.net/anime/11531" rel="nofollow">UN-GO Episode 0 - Inga-ron</a> (a prequel to <a href="http://myanimelist.net/anime/10798/UN-GO" rel="nofollow">UN-GO</a>)</li>
<li>Also, <a href="http://myanimelist.net/anime/20723/Kyousou_Giga_%28TV%29_Specials" rel="nofollow">Kyousougiga Episode 0</a> is a recap of <a href="http://myanimelist.net/anime/15359/Kyousou_Giga_%282012%29" rel="nofollow">the Kyousougiga ONAs</a>, which are sort of pilot-y with respect to the <a href="http://myanimelist.net/anime/19703/Kyousou_Giga_%28TV%29" rel="nofollow">Kyousougiga cour-length anime</a></li>
</ul>

<p>There's a lot of prequels and pilots<sup>1</sup> here. Prequel episodes typically occur chronologically before "episode 1" in terms of show timeline, while pilot episodes typically occur chronologically before "episode 1" in terms of the real world, and so it makes sense for either a pilot or a prequel to be numbered "episode 0". </p>

<hr>

<p><sup>1</sup> By "pilot", I mean any short piece that airs before a longer anime, whether or not it's a <a href="http://en.wikipedia.org/wiki/Television_pilot" rel="nofollow">pilot in the US television sense</a>, so this label includes teasers, animation test runs, etc.</p>

CC BY-SA 3.0
2013-12-21T23:37:36.553Z
2013-12-21T23:37:36.553Z
senshin
<p>I don't know that many or most anime use the Episode 0 format, but a few exceptionally popular series will do whatever they can to continue making money. Extra DVD episodes with full box sets, Episode 0 prequels, theater-release movies are all ways anime series can continue to maintain fan interest after the series has finished on TV.</p>

<p>Other ways series keep or increase fan interest is licensing goods, radio shows, Drama CDs, live events and manga creator appearances.</p>

<p>Anime is a corporate product and corporations want to make money.</p>

CC BY-SA 3.0
2013-12-21T01:50:06.713Z
2013-12-21T01:50:06.713Z
abkds
<p>In the anime I've been watching lately, I see a lot of episode 0s popping up, which usually are published after the final episode and usually are not very comprehensible unless you have watched the series itself.</p>

<p>Where did this originate from and why do they do this?</p>

<p>Sample show:</p>

<p><img src="https://i.sstatic.net/8wKYf.png" alt="list of Kyousougiga episodes"></p>

CC BY-SA 3.0
2013-12-21T05:06:55.903Z
If I had to take a guess, I would say episode 0 is almost like an adaptation of chapter 0. Chapter 0 was the oneshot (a single chapter of a story), and if the oneshot was successful, then the story turns into a manga, gets serialized and published as a series. Thus episode 0 would basically contain the contents of chapter 0.
krikara
CC BY-SA 3.0
2013-12-21T13:09:23.983Z
@krikara that does sound some what logical
Dimitri mx
CC BY-SA 3.0
2013-12-21T23:18:14.123Z
Based on a brief MAL search for "episode 0", it looks like most episode 0s are either pilots or prequels. In both cases, the numbering makes sense - prequels are in-show chronologically before episode 1, while pilots are real-world chronologically before episode 1.
senshin
<anime-production>
Where does the idea of "Episode 0" originate from?
# Where does the idea of "Episode 0" originate from?
Posted by: username_0 on 2013-12-21
In the anime I've been watching lately, I see a lot of episode 0s popping up, which usually are published after the final episode and usually are not very comprehensible unless you have watched the series itself.

Where did this originate from and why do they do this?

Sample show:

![list of Kyousougiga episodes](https://i.sstatic.net/8wKYf.png)
**Tags:** anime-production
> **Comments:**
> **username_1**: If I had to take a guess, I would say episode 0 is almost like an adaptation of chapter 0. Chapter 0 was the oneshot (a single chapter of a story), and if the oneshot was successful, then the story turns into a manga, gets serialized and published as a series. Thus episode 0 would basically contain the contents of chapter 0.  
> **username_0**: @krikara that does sound some what logical  
> **username_2**: Based on a brief MAL search for "episode 0", it looks like most episode 0s are either pilots or prequels. In both cases, the numbering makes sense - prequels are in-show chronologically before episode 1, while pilots are real-world chronologically before episode 1.  
---
## 2 answers
### Answer by username_2 on 2013-12-21. Score: 4 | Accepted answer
Based on a google search for [`site:myanimelist.net "episode 0"`](https://www.google.com/search?q=site%3Amyanimelist.net+%22episode+0%22), we find the following episodes:

* [Candy Boy Episode 0](http://myanimelist.net/anime/3456/Candy%E2%98%86Boy_Episode_0) (a pilot, airing 6 months before [Candy Boy](http://myanimelist.net/anime/4535/Candy%E2%98%86Boy))
* [Nichijou Episode 0](http://myanimelist.net/anime/8857) (a pilot, airing a month before [Nichijou](http://myanimelist.net/anime/10165/Nichijou))
* [Haganai Episode 0](http://myanimelist.net/anime/10897/Boku_wa_Tomodachi_ga_Sukunai_Episode_0) (a pilot, airing a few weeks before [Haganai](http://myanimelist.net/anime/10719/Boku_wa_Tomodachi_ga_Sukunai))
* [One Piece: Strong World Episode 0](http://myanimelist.net/anime/8740/One_Piece%3a_Strong_World_Episode_0) (a prequel to [One Piece: Strong World](http://myanimelist.net/anime/4155/One_Piece%3a_Strong_World))
* [Koroshiya 1: Episode 0](http://myanimelist.net/anime/2346/Ichi_The_Killer%3a_Episode_0) (not sure about this one - Japanese Wikipedia says that it's about Ichi's past, so I guess it's a prequel?)
* [Hakuouki Hekketsuroku Episode 0](http://myanimelist.net/anime/2346/Ichi_The_Killer%3a_Episode_0) (a recap of the first season, and hence a sort of "prequel" to [the second season](http://myanimelist.net/anime/9065/Hakuouki_Hekketsuroku), which aired a week later)
* [Ichigo Mashimaro Episode 0](http://myanimelist.net/anime/4156/Ichigo_Mashimaro_Episode_0) (not sure about this one; it may be worth noting that it's called "Prologue" rather than "Episode 0" in Japanese)
* [UN-GO Episode 0 - Inga-ron](http://myanimelist.net/anime/11531) (a prequel to [UN-GO](http://myanimelist.net/anime/10798/UN-GO))
* Also, [Kyousougiga Episode 0](http://myanimelist.net/anime/20723/Kyousou_Giga_%28TV%29_Specials) is a recap of [the Kyousougiga ONAs](http://myanimelist.net/anime/15359/Kyousou_Giga_%282012%29), which are sort of pilot-y with respect to the [Kyousougiga cour-length anime](http://myanimelist.net/anime/19703/Kyousou_Giga_%28TV%29)

There's a lot of prequels and pilots1 here. Prequel episodes typically occur chronologically before "episode 1" in terms of show timeline, while pilot episodes typically occur chronologically before "episode 1" in terms of the real world, and so it makes sense for either a pilot or a prequel to be numbered "episode 0".

---

1 By "pilot", I mean any short piece that airs before a longer anime, whether or not it's a [pilot in the US television sense](http://en.wikipedia.org/wiki/Television_pilot), so this label includes teasers, animation test runs, etc.
---
### Answer by username_3 on 2013-12-21. Score: 0
I don't know that many or most anime use the Episode 0 format, but a few exceptionally popular series will do whatever they can to continue making money. Extra DVD episodes with full box sets, Episode 0 prequels, theater-release movies are all ways anime series can continue to maintain fan interest after the series has finished on TV.

Other ways series keep or increase fan interest is licensing goods, radio shows, Drama CDs, live events and manga creator appearances.

Anime is a corporate product and corporations want to make money.
---
