Farewell, Unova! Setting Sail for New Adventures!

After the Team Plasma escapades, Ash decides to return to Kanto with Iris and Cilan wanting to go there to continue their quests to be Dragon Master and Pokémon Connoisseur respectively. Following Juniper's suggestion, Ash & Co. decide to take a ferry which goes through the Decolora Islands. However, when they get on the ferry, they soon learn that everything is not as it seems when simple doors refuse to open. It turns out Team Rocket are in command of the ship...