Fun With Numbers: The (Relatively) Predictable Light Novel Adaptation Market

In the past several weeks, Ohayocon-induced hiatus aside,* I’ve been compiling the sales data of light novels that became anime in 2011 and 2012. Put bluntly, the ecosystem of initial print sales->anime sales->additional print sales is very, very different from manga. With manga, it was very often the case that a comparatively unpopular manga like Blue Exorcist could produce the anime sales of a superhit while a way more popular manga like Sukitte Ii Nayo could produce anime sales all too close to nonexistent. Additionally, poor-selling anime like Kamisama Dolls and Zetsuen no Tempest often led to big surges in manga sales while popular anime like Yuruyuri produced negligible manga gains.

With light novels, that sort of thing can still happen, but it’s far rarer. In general, there are two dominant trends in the light novel market. One, better-selling light novels produce better-selling anime. Two, better-selling anime produce bigger increases in light novel sales. Though it should be noted, as always, that the extent to which this effect carries does vary somewhat.

To recap something I touched on here, Pearson correlation coefficient is a number between -1 and 1 that indicates a stronger correlation the further it is from zero.

Let’s examine that relationship in a little more detail. Popular Light Novels (arbitrarily defined here as novels that had at least one 2-week period in which they sold over 15000 volumes prior to the anime) accounted for every LN-anime to average over 4000 disks sold per volume except Cap’ns Katou and Satou’s Glorious Space Piracy Joyride. This leads to a Pearson correlation coefficient of pre-anime LN sales and anime sales of 0.68, indicating a fairly strong relation. According to a linear fit of the data, after 15000 volumes, every 100 LNs added to the pre-anime peak is worth about 70 additional disks per volume sold. With the understanding that there’s scatter and most series do better or worse than average, of course.


And once an anime becomes popular for the same reason its source material was, you can generally count on LN sales to ride what could be considered their own coattails and rise significantly. Save for anvil substitute Horizon on the Middle of Nowhere, every anime-LN adaptations that averaged over 10,000 disks sold added 20,000 or more to the sales average of its respective LN franchise. The Pearson correlation coefficient anime sales average and increase in LN sales averaged over the 4 volumes nearest the anime (2 before and 2 after) is an even stronger 0.74. According to a linear fit, every 100 anime disks sold will correspond to 170 additional light novels sold per volume.


When I was looking at manga sales gained, I happened to notice that a series’ rank on myanimelist happened to correspond fairly well with gains in manga sales. Though comparing myanimelist ranking does produce a stronger correlation coefficient with print gains (-0.4, as opposed to -0.25), compared with a manga sample where the series that got big gains were almost exclusively in the top 1000, the sample is a bit less visually striking.


What is visually striking is the correlation of LN sales gained with myanimelist popularity. Here, the 3 LNs that got the biggest gains all got them from anime in the top 200, and no LN with an adaptation in the top 200 gained less than an average of 20,000 volumes. Couple that with a steeper linear fit on average. The correlation coefficient for LN print sales gained and mal popularity is -.64, compared with -.23 for manga print sales.


My pet theory/explanation for this discrepancy in the importance of popularity between media is this; the type of people who would never buy light novels anyway are bringing the ranks of the anime down, but light novels are niche enough that they don’t need mainstream approval. Perhaps the series are still reaching the people they want to reach, doing so in appreciable large numbers.

One other interesting thread arises out of the conclusion. I have 60 manga adaptations on record over these two years, compared to only 37 LN adaptations. If light novel adaptations, especially those of popular series, produce better-selling anime more reliably than manga, why do we see fewer adaptations of them of them than we do of manga?

The likely answer comes from the fact that anime in general don’t just profit from selling disks. They’re also often made to promote their source material, and the fanbase for manga in Japan is significantly larger than the fanbase for light novels in Japan. Consider that the highest-selling light novel used in this sample, Sword Art Online, was selling ~200,000 new volumes in a 2 week period after getting its anime bump, and compare that with the fact that that there are at least 3 manga (One Piece, Fairy Tail, Attack on Titan) that can sell one million copies in an equivalent frame of time. And mix in the fact that the last one of that group of three is on there at least in part thanks to its anime. Despite the apparent overlap of those who buy anime with those who buy light novels, the print sales upside of manga adaptations is a huge point in their favor.

A more thorny question is one I don’t have a clear answer to is this; why adapt light novels in the bottom of the sales tier (i.e. under 10,000)? This 2011-2012 sample suggests that it’s not a great idea. Even if a 10-episode anime averages around 2000 disks and produces a gain in LN averages of 10,000 over the next 5 volumes, that only adds the equivalent of 10000*5*500/(5*7000)=714 additional disks to the anime average, producing a total still well below the break-even mark.

It’s possible that LN consumers are more likely than manga consumers to backbuy every volume, which would raise that total a bit for long-running series, but there’s not a ton of numerical justification for low-selling light novels getting adaptations.** If the industry hits another wall like it did in 2008, adaptations of these types of series might be finding their way to the pre-production chopping block considerably more often, perhaps with budget refocused into developing younger writing talent.

*Aside from the panel on noitaminA that some genius scheduled for 1:30 AM which predictably got zero attendees, the con was generally excellent. I’d like to think that people walked a away with a little more understanding of the gears that make up the anime/manga machine.

**This is one of the reasons why I would totally take pick ’em odds on the upcoming Amagi Brilliant Park adaptation averaging less than 3000 disks per volume. The arguments for it are Kyoto Animation’s buy-anything base, a fictitious construct of people who only bother to pay attention to figures that support their cause and ignore the fact that Munto did badly enough to join the illustrious ranks of shows never to make the oricon charts, and the fact that it’s being made by the creator of Full Metal Panic, an argument that holds up until you realize that Golden Time is from the creator of Toradora (which sold considerably better as an anime than FMP) and sold moderately worse this August than Golden Time did this April. The arguments against Amagi are the fact that the top reviews of its first two volumes on amazon are ones that rate them 2 stars out of 5, and the fact that the only LN adaptation to overcome sales figures at or below Amagi’s level and be successful in these two years is the aforementioned Bodacious Space Pirates. In more general terms, breaking 3k is something the majority of anime series do not do; Tamako Market’s ~3600 disk average was in the 70th percentile of anime sold from 2005-2012.

Purely going by LNs that peaked at Amagi’s current level or below in these two years, the odds of it breaking 3k are 1 in 7. Even if you think Kyoto Animation triples those odds of success, that’s still 2 to 1 against. Hardly impossible, but definitely an uphill battle.

15 thoughts on “Fun With Numbers: The (Relatively) Predictable Light Novel Adaptation Market

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  2. Seeing Tokyo Ravens’ LN and anime sales, can someone answer this: was there a significant sales boost for the LN? If so, is it considered good or not?

    • Depends. The Tokyo Ravens LNs coming out prior to the anime had pretty consistent totals, and we haven’t seen anything in the main series out after (one of the reasons I picked 2011-2012 series is because, aside from maybe 2010, they’re the only years we have before *and* after data for). v10 came out in October, so there may or may not have been a boost. Once v11 comes out, we’ll have a much better idea as to how that fared.

      2-Week Totals for Recent TR Volumes:
      20,387 Tokyo Ravens vol.7 (May 2012)
      19,820 Tokyo Ravens Vol.8 (October 2012)
      18,914 Tokyo Ravens Vol.9 (March 2013)
      23,123 Tokyo Ravens Vol.10 Begins/Temple (Oct 2013)

      The EX series has seen a bit of a boost in its 2-week totals post-anime, to the tune of about 8000 copies.

      14,441 Tokyo Ravens EX1 party in nest (July 2013)
      22,206 Tokyo Ravens EX Vol.2 (Feb 2014)

      That could be more or less than the main series got, but if it’s in the same ~10k plus/minus 5k additional copies per volume range, then that puts it at an average to slightly below-average bump. That can still be pretty nice for the publisher, since they don’t have to pay more to keep the customers interested now that they’re buying the series. Each additional volume the series comes out with makes the anime bump more valuable. I haven’t had occasion to study long-term effects of it, but I’ve seen evidence that the bump for mid-tier manga can be very permanent.

      If you’re talking about “will we get a sequel because of LN effects” good, these numbers are unlikely to spur one. The argument for season 2s working as effective print media advertisements is very fragmentary. Kore wa Zombie is the only arguable example I’m aware of, and that averaged 800 disks above the 2.2k TR is at now with a bump in the 20k+ range. Nothing’s impossible so long as the source material is going, but I wouldn’t bet money on it.

      • By the way, what are recent examples of recent anime based on manga/LNs/video games etc. where the anime flopped and the source material had little-to-no boost? And among these anime, were any of them cancelled?

        • Code Breaker, Zetman, and Hyouge Mono are all series that sold poorly and produced no visible manga boost. Itsuka Tenma no Kuro Usagi and OniAi are LN examples of a mild flop anime + no LN boost where the source continued for several volumes after the anime.

          It depends what kind of cancellation you’re talking about. To date, I don’t know of a single example modern late-night era case where an anime was deprived of its originally planned runtime (original Gundam was, but that was a long time ago and a daytime timeslot). As far as I know, the typical seasonal anime arrangement puts studios under contract to make a season worth of episodes and that contract is already locked in before the anime begins airing, so there’s little to no reason for the production group to not make and subsequently air the series to try and recoup what losses they can. Barring a contract-cancelling PR gaffe of the kind that got the OP of Hyouge Mono (musician arrested on drug charges) or the ED of Daily Lives of High School Boys (musician talked very public smack about Horie Yui) changed, but on a much bigger scale, I don’t think cancellation of an anime is a realistic outcome.

          In general, anime work contracts are short enough that, most of the time, it’s much easier to just let the terms play out than bring in negative attention by cancelling it. It’s very like Shueisha’s half-year policy for giving new Jump artists a try; the anime industry just necessitates it more because of the higher costs involved with a long-running flop anime.

          Dragon Crisis is an LN example of a series that ended soon after the anime did, which may or may not have just been a planned ending. Ditto for Code Breaker. In general, though, it actually makes sense to run a series that gets even a moderate boost for a few years after the anime, whether manga or LN, since it maximizes the positive effects of the boost without costing anything beyond than the normal price of paying authors.

          • When I said “cancelled”, I meant that the show’s source material ended/was cancelled shortly after the anime aired (and flopped). What are examples of these cases? I know C3-Bu is one. Also, if Amagi flops, is it likely that the LN will get cancelled?

            • It’s hard to say. I can give examples of 2011-2012 series that saw significant source material boosts and ended soon after the anime (Gosick, Kamisama no Memochou) and ones that saw no boost and continued for some time (Kuro Usagi, Sankarea) in addition to those that did end within 1 year of the anime (Dragon Crisis, Code Breaker). Those are enough conflicting examples that I’m not sure how strong the causal relationship there is.

              Despite the potential gains from a boost, some LN/manga series do plan their endings around the anime’s ending. Toradora and FMA (hits) and the aforementioned Gosick/KamiMemo (low/mid-tier) all did so. Golden Time is setting itself up to be the latest example. C3-bu’s 3 volume/1year print run would have been pretty typical for a monthly promoted-from-webcomic series without an anime that failed to make the Oricon charts at any point during that run. Whether or not that was a “cancellation” or an author-planned ending likely depends on how conclusive the finale of the series was (i.e. did it enter into a “final arc” 5 or 6 months prior to the actual ending?).

              Anime is an important part of the advertising strategy for print media, but these industries are plenty profitable on their own, and much bigger than the TV animation industry as a whole. There were at least 30 manga in Japan which sold over 1.5 million volumes last year. The gross from one of these series is about 1.5mil*500 yen~750 million yen. The typical 1-cour anime budget is only about 200-400 million yen (per Justin Sevakis). One failed anime (while not nothing) is a lot smaller of a deal for manga publishers than one would think, especially since even relative flops with 2k or 1k averages make back some percentage of that budget. It’s easy to overrate the importance of anime because we see so much more of it in the west, but manga is a much broader and more lucrative industry, and manga can generally continue so long as they continue to sell passably well.

              As a rule, most light novels and manga that are popular enough to chart above the unfriendly Oricon thresholds are profitable enough to continue irrespective of the effects of anime *if the author wants to keep writing*, unless they run in a major magazine like WSJ or WSM where the publishers are aggressively trying to farm 100k/volume sales megahits, in which case they probably won’t last long enough to get an anime at any rate.

              There’s a real danger of drawing the sexy conclusion that the anime was the determining factor when the LN or manga publication side may play an equal or greater role in deciding things. In Amagi’s specific case, there’s not strong precedent that would tell us much either way. Not that its continuation for sure doesn’t hinge on the anime, but there’s no indication that that will be the decisive factor. The 15k per volume it’s been steady at is respectable for a light novel (just not a positive indicator for what the anime disk sales will be), so I think it’s going to come down to whether or not Shoji Gatoh feels like doing more of it.

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  4. In the case of C3-Bu, the anime’s ending was announced just one month after the anime ended, and, although I didn’t read the manga, IIRC the end was announced a bit all of a sudden, and they weren’t entering a “final arc” (It’s a slice-of-life, so there normally wouldn’t even be such things as arcs).

    • C3-bu has components of both SoL and battle series; at the very least, there are storylines within the translated portion of manga that stretch out over multiple chapters (10-12 take place over a single day). Without having read the untranslated chapters, I think it’s at least plausible that they spent a few weeks setting up a climax. I’d have to actually check the raws to find out.

      Also, just because it was announced then doesn’t mean it wasn’t being planned prior to that. Sudden announcements of cancellation are the norm for non-hit manga. Kodansha has announced the shuttering of whole magazines (most recently Kiss Plus, whose final issue contained the first announcement that it would be the final issue) with less fanfare. Mx0 regularly made the top 10 on the oricon charts and was cancelled with less than a month’s warning (late April announcement, mid-May final chapter). This is not to say that the anime didn’t have anything to do with it, just that there’s a fairly substantial baseline which says it doesn’t have to be the primary cause.

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    • I go by two-week totals (comparing like-like), and we don’t have those yet, but the first-week sales for volume 11 were about 16k, or 5k more than volume 10’s total. Two week total will probably be around 25k-35k, not sure exactly how much. If it’s 30k, that’d be about 10k per volume, similar to what the EX series got. So it’s a significant, albiet average-ish, gain.

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