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Donto Island (Japanese: ドント島 Donto Island) is an anime-exclusive location in Date Expectations, located between Mirage Island and Pacifidlog Town. It is home to a large number of Donphan. Even though it seems unpopulated by humans, it does have a small harbor on one side of the island, which has a ferry service to Pacifidlog Town.
Ash, Brock, May, and Max were on their way to Pacifidlog Town for May's final Contest when the engine of the boat they were on broke. The captain, Carlos told them that it might take a few hours to fix and that they should be able to take the boat to Pacifidlog Town on the other side of Donto Island.
Ash and his friends stepped foot onto the island and soon encountered its resident Donphan. They were attacked by a Donphan that used Rollout but stopped it with the help of Mudkip, and Corphish. They became friends with this Donphan and learned that it was attracted to a female Shiny Donphan. At first, the female Donphan wasn't interested in the Donphan Ash and his friends helped, but after taking on Team Rocket, the pair fell in love.
The group finally reached the other side of the island, narrowly missing the Pacifidlog-bound ferry. However, Carlos returned with his repaired boat and he managed to get Ash and his friends to their destination.
Pokémon seen on Donto Island