Thinking of becoming a rich and famous manga artist? These stats might give you pause.
In 2009, some 5300 tankobon (volumes of a manga series) were published in Japan. The top 100 averaged a whopping 70,000,000 yen in royalties for their artists -- that's about $900,000 a volume annually for the top performers. Not bad! Sounds like a pretty good living.
But what about the remaining 5,200 artists out there? Their average annual royalty income was just 2.8 million yen -- about USD $35,000. For a year of work. Not counting expenses, of which a manga-ka has many. Not exactly conducive to a rockin' lifestyle, especially if you're living in one of the world's most expensive cities. And remember, that's the AVERAGE. Which means a significant amount are making significantly less than that.
The bottom line? It's extraordinarily difficult to earn a "middle class" standard of living as a manga artist. (Added 6/1: As mentioned in the comments, it's estimated one has to sell 120,000 copies of their works to even match the average salaryman's annual income.)
(Correction 5/31: yes, I know I missed a zero in there at first. It's been fixed. These are the correct figures.)