Gintama Season 3 Episode 37: Shogun Assassination Arc Part Three: Ninja Soul
Episode 37 of 51 of Gintama Season 3, aired December 15, 2015, 25 minutes. Available with English subtitles and dub where released.
Episode summary
After it becomes clear that the Iga clan didn't actually betray the Shogun, Gin and co are taken to their village and learn the truth about the Shogun's deep involvement with the clan in the past.