Gintama Season 3 Episode 16

Overview
While Gintoki, Shinpachi, Kagura, Hasegawa, Tae, Kyuubei and Katsura are on their way to the legendary Dragon Palace, a quarrel between them ends up bringing them onto an isolated island.
Episode Title: Summer Vacation is the Most Fun Right Before It Begins
Air Date: 2008-07-17
Year: 2008