Shueisha revealed on Monday that Hideaki Sorachi 's Gintama manga has more than 50 million copies in print in Japan. The manga's 64th volume (pictured at right) shipped on Monday.

Shueisha released an official app for iOS and Android for the manga on Monday to commemorate the announcement. The app will eventually feature all volumes of the manga available to read for free, and it is adding one new free volume each week.

Sorachi began the manga in 2004 and it continues to be ranked among the top-selling manga in Japan. Sorachi previously reported that he is starting the manga's final arc this year, although he himself does not know if the manga will end this year or next year. Viz Media published the first 23 volumes in English.

The manga inspired a television anime that premiered in 2006 and continued (with several extended hiatuses) until 2013. The latest Gintama television anime series premiered in April 2015, and ended in March. Crunchyroll streamed the series as it airs in Japan. The manga also inspired two anime films, including the "final" Gekijōban Gintama Kanketsu-hen: Yorozuya yo Eien Nare film that opened in 2013, and various OVAs and event anime.

Source: Anime! Anime!