One of the most fundamental issues I take with English-language discussion of anime is the degree to which many people simply ignore manga outright. From a demographic perspective, this makes sense; Japan spends roughly 5 billion dollars on manga every year, and in France, the annual income in dollars of the manga industry (~125 million) exceeds the number of people living in the country (~66 million), but the average United States citizen spends about 38 cents per year (120 million per year market, 318 million people) on manga while pirating or illegally streaming approximately 6 gazillion episodes of anime. Ok, I made that last figure up, but I did plug in the 2 sites that “free streaming anime episodes” pulled up for me on google into a web value calculator, and those sites, gogoanime and kissanime, have a combined estimated pageview total of 1.5 billion per year, and they’re hardly the only ones out there that do what they do.*

It’s worth noting that I’m not at all unbiased about this; manga is kind my favorite thing. And that’s why I fall into the devil’s advocate role when people try to build anime-centric narratives surrounding manga. One of the most common permutations of this phenomenon pops up when a manga series ends soon after an anime adaptation of it. I’ve seen it argued in different places that poor anime performances killed off C3-bu, Daily Lives of High School Boys, and Binbougami ga. The most oft-cited piece of evidence in these cases is the timing of the ending of the series; if the franchise became more popular, it wouldn’t make sense to end it in the middle of that boom. The issue with that line of reasoning, though, is that authors can and have quit on extremely popular series at multiple times in the past. Inoue Takehiko ended 100,000,000+ seller Slam Dunk in the middle of a major tournament, and Hiroyuki Takei ended Shaman King early for health reasons. At the very least, author burnout is an alternate hypothesis that needs to be addressed, either with additional evidence for the “cancelled” argument or a direct quote from the author. Since the latter is only available on a case-by-case basis, I’ll be taking a look at the first question; does a lack of a visible sales boost increase the odds that a manga will end a year or so after the anime adaptation?

I’ve previously studied the adaptation boosts of manga and light novels made from 2010-2012 in regards to their effects on series getting second seasons. I’ll be using the same data, with the same qualifications for a boost (20% increase in sales averaged over 2 volumes pre and post anime, or charting for the first time 1000 copies above the lowest previous threshold). I compared the frequency of series getting boosts among those that ended one or two years after the first season of anime** with the frequency among those that ran more than 2 years or are still running. The original sample contained 82 shows, but I excluded 3 (Space Brothers, Toriko, and High School of the Dead) because the anime either ended less than 9 months ago or the series is on hiatus, leaving the final sample with 79 manga that received adaptations over this 3-year period.

Of those 79 manga, 16 continued for less than a year after the first anime season ended, 8 continued between 1 and 2 years, and 55 continued for at least 2 years. 9 of the <1yr sample got boosts, 6 of the 1yr<t<2yr sample got boosts, and 32 of the >2yr sample got boosts. This works out to the following rates of boost occurrence in each subsample:

t<1yr: 56%±14%

1yr<t<2yr: 75%±26%

t>2yr: 58%±8%

Basically, all are within the margin of error. If anime boosts have an effect on series runtime, it’s not a big enough one to be at all evident over a three-year sample.

Compare those ambivalent figures with the popularity of the manga versus its magazine. Via mangahelpers, I was able to get recent magazine circulation figures for many series in this sample. I then compared the sales of the magazine with the 2-week total of the manga’s first post-anime volume,*** getting a figure that was negative if the magazine circulated more copies and positive if the manga circulated more copies for the 40 series in the sample for which both numbers were available. The rationale here is that a manga outselling its magazine is more likely to be one the magazine wants to keep running. 78%±18% of series with a positive differential ran at least 2 years after s1 of the anime ended, compared with 59%±12% of series with a negative differential. A seemingly large difference, but still within the margin of error.

The real difference comes in when you compare the series with a negative differential in excess of one million; those series, exclusively from WSJ/WSM, only outlasted the anime by 2 years 25%±8% of the time; without them, 79% of the series with negative differentials are actually running 2 years or more. This is a function of the way very large magazines work – if a series is only doing “okay” by megahit standards, it’s easy for the publisher to nudge it towards an ending because of the Assassination Classroom-tier upside new series in major publications can have. Why settle at 80k/volume for 10 volumes when you can take 4 reasonable shots at a 400k/volume powerhouse in the same time period?

While it’s not out of the question that an adaptation not to the author’s liking can sour their attitude towards the series, it generally makes very little economic sense to end a manga because of an anime; anime are paid for in advance, and if a manga is popular enough that you’re considering making an adaptation for it (and you’re not a magazine with 1 million plus copies in circulation that can easily duplicate those figures with a new series), running it longer is generally going to produce more revenue than ending it soon. Without author quotes or some other evidence to back it up, the fact that a manga ended soon after the anime is not, by itself, meaningful.

*Crunchyroll is estimated to get about 2.1 billion pageviews per year. Free manga sites like batoto.net (0.5 bn/yr) and mangafox.me (5 bn/yr) also have large pageview count estimates, but that’s somewhat inflated by the fact that reading a 5-volume manga involves clicking through roughly one thousand pages, while watching a one-cour anime involves 12.

**I counted a series as having ended a year after the anime if they ended in the same month one year apart, even if the manga ran slightly longer. Ditto for two years.

***Post-anime in this case means it came out at least 2 months after the anime aired. As the glorious 70k WCW v7 total recently showed, boosts often take a while to showcase their full effect.