Towards the end of 2011, the chief editor of comic Yuri Hime, Naitarou Nakamura, revealed that Yuruyuri, a then-7-volume manga series which was adapted into an anime series in summer of that year, had sold over 1 million copies. That in itself isn’t a particularly rare feat; 49 different manga sold that many copies in 2011 alone, as did 15 individual volumes.

What makes Yuruyuri’s case particularly instructive, though, is that it had never appeared on the Oricon charts until June of 2012, 6 months after hitting said million copy mark. How is it possible that a series can hit that impressive a milestone without charting once? The short answer is that the Oricon charts are a very incomplete list. In the past 5 years’ worth of manga charts, we’ve never had a threshold that was below a five-digit number of copies. That means that, in theory, it’s entirely possible (if not extremely likely) for a series to sell 10,000 copies per week without its fans hearing a word about it. If this hypothtetical volume did that for 52 weeks, its total sales of 520,000 volumes would be 25,000 copies shy of the last series on the 2011 top 50 individual volumes list (One Piece’s first volume).

The above example is a bit extreme, but Yuruyuri’s performance isn’t that far off. There is a fairly strong limiting case we can look at to get an idea for how exactly Yuruyuri made it to the magic million (which required an average of ~143,000 copies sold per volume);  Assume the sales were entirely fueled by the anime’s popularity boost. The series had 7 volumes out for the period between the anime airing (on July 4th). Between July 4th and December 18th, there were a total of 24 weeks of Oricon sales charts. 1,000,000 copies/7 volumes/24 weeks=5950 copies/volume/week. The lowest threshold over that time period was 18,406 copies/week for one week in mid-October. Even if we assume that all of those sales were packed into the 12 weeks in which the anime was airing, that’s only up to about 11,900 copies/volume/week, still short of the most generous available threshold over that time period. In a less stringent case, if the manga was already half of the way to a million copies and the anime provided a more moderate boost (which would still have been doubling the series’ sales in a quarter of its previous 2 years in print), it would have been even easier for the series to remain entirely under the radar en route to the million-copy mark.

Yuruyuri had a successful anime, averaging about 8348 disks per volume, and thus didn’t need the manga success the way a lesser series might have. But it does serve as one of the more powerful counters to the idea that the success of a anime in advertising a manga necessitates an appearance on the Oricon charts. It also illustrates the fact that, when actually see big boosts in sales, those might be significantly bigger than just what we observe. The most successful manga advertisements, the crazy-chart Blue Exorcists, are easy to quantify. However, many series, even those that end up as clear-cut successes from an insider’s point of view, are not.* One thing that should always be kept in mind, especially when looking at manga for adults like Aoi Hana that packs a per-volume price tag (~1030 yen) twice that of newer One Piece volumes (~430 yen), is that a series doesn’t have to be making the Oricon charts at all to make its publisher happy.**

*I am guilty of oversimplifying these cases myself at times, so I can’t really blame other people for doing so. To wit, the gain-probabilities I name in this article are for minimum gains, not exact gains.

**Yuruyuri, by the by, runs about 930 yen/volume.