One of the interesting tidbits that fell out of my research on manga that got anime in 2011 was the surprising coincidence of high (1500th or better) myanimelist rankings and increased manga sales. At least, it was intriguing enough that I decided to delve into it further, pulling sales figures for the 20 manga which both got anime and charted on the Oricon rankings in 2012. The full analysis is coming, but, short version, there’s a 90-plus percent that that correlation is a very real thing, indicating a strong link between the opinions of myanimelist users and the Japanese manga-buying public, to the extent that I might even be able to plug it in to my sequel probability equation and get the “can’t predict loss-leader effects” monkey partially off the sequel probability equation’s back.

All of which makes Thermae Romae, which presided over a 100k+ increase in week one sales of its manga while posting a piddling rank of 2248th on myanimelist, a case worth a closer look.* Is the jump in average week-one sales from 222,000 volumes for 3 and 4 to 323,000 volumes for 5 and 6 indicative of the effects of the anime, which began and ended between the releases of 4 and 5?I’d lean towards “no”, for one primary reason. In the interval of time separating the releases of volumes 4 and 5, the anime wasn’t the only thing to happen. Namely, a live action movie which spent three whole weeks atop the Japanese box office, grossing a total of over 36 million US dollars in that time period. It’s very possible, given the anime’s subpar reception both on TV and in a myanimelist ranking that usually correlate pretty well with gains by the manga, that the film owns the lion’s share of the credit.

What does this mean for Space Brothers, a series with a similar movie/anime combo that debuted in the gap between the releases of volume 17 in March and volume 18 in June? Well, it’s doubtful the effects of the Space Brothers live action were as strong as the effects of Thermae Romae’s were; the movie got its ass kicked at the box office in its release week by the second-week tail of Thermae Romae, whose first week grossed five times as much. But the gain in first-week manga sales per volume from 16 and 17 to 18 and 19 was actually slightly higher than TR’s total (113,000 to 216,000=a change of 103,000>101,000). And it happened for a monthly series with a more frequent release schedule. The anime, currently ranked a stronger 187th on myanimelist, likely played more of a role in that case. But the presence of a film is still worth noting, both in this case and in general, when attempting to gauge the effects of various factors on the performance of manga.

*If you watched it, you don’t need me to tell you that a flash anime about a roman man coming to Japan through a hot bath time machine and stealing futuristic bath sociology is unusual, but still.