Bundled with limited edition of the 58th Gintama manga volume.
The tagline for the bundled anime reads, "It's time for all the Yorozuya members ...to wake up just one more time."
(Source: MAL News, edited)This special Gintama episode was previewed at a screening at Jump Special Anime Festa 2014. On April 3, 2015, it was bundled with a limited edition of the manga's 58th volume.
Visit Gintama: Jump Festa 2014 Special on MAL