Hajime Isayama's smash-hit manga Attack on Titan has surpassed 50 million copies in print worldwide, according to the Japanese entertainment site Eiga.com.

For a bit of context, Anime News Network notes that in April, when the 16th volume was released in Japan, that figure was at 44 million. Kodansha Comics USA, the North American subsidiary of Japanese publisher Kodansha, announced last month that 2.5 million copies of the English-language editions are in circulation (the translation of the 16th volume will be released later this month).

Expect that those numbers to rise again significantly, and relatively rapidly: The first of two live-action adaptations opened over the weekend in Japan, to be followed later this month by a live-action TV miniseries, and then an anime series based on the spinoff manga Attack on Titan: Junior High and, eventually, the second season of the blockbuster Attack on Titan animated series. The films will receive North American release, presumably sometime this fall.

Debuting in 2009 in Kodansha's Bessatsu Shōnen Magazine, Attack on Titan is a post-apocalyptic fantasy set in a world where remorseless, flesh-eating giants have all but wiped out humanity, whose remnants are forced to live within a country surrounded by three enormous walls. The story initially centers on Eren Yeager, his adopted sister Mikasa Ackerman and their childhood friend Armin Alert, who join the military to fight the Titans after their hometown is attacked and Eren’s mother eaten.

Credited earlier this year with driving the turnaround of manga sales in North America, Attack on Titan was edged out -- if only barely -- by perennial favorite One Piece as Japan's top-selling manga in 2014: One Piece sold an estimated 11.9 volumes, while Attack on Titan moved 11.7 million.