Hyokaido is an island that is located in Paradise and this place is known for its cold climate and is filled with icebergs and glaciers. This is the territory of the Accino Family.
Hyokaido is a frigid island that is surrounded by icebergs and glaciers that were formed over a hundred years. This island had many waterways for the ships to pass through. But as there are many icebergs, which have unnatural movement, they can trap ships. Most of Hyokaido is a barren ice land.
Hyokaido is the main territory of the bounty-hunting Accino Family. They have a massive golden castle with their own tropical rainforest which is different from the rest of the frigid environment. The Accino Family would bring their captured pirates here and then imprison them in an icy cavern.
The Domo Penguin is a type of penguin that is native to Hyokaidoa and they look like the Blue Rockhopper Penguin with a Puffin beak. They move in large groups as it helps them move the various icebergs in Hyokaido from underneath. These penguins are very vicious and they can cause trouble to anyone that comes in their way.
Hyokaido is a reference to the northern Japanese island Hokkaido.
Hyokaido is an anime-only island and is not mentioned in the manga.
Hyokaido was shown during the Ice Hunter Arc.
The Domo Penguins are the ones who consciously move the icebergs in Hyokaido.