The Akaei of Ehon Hyaku Monogatari exposes an island-sized body above the water. Sand, pebbles, and seaweed rest on its back, so from a distance it looks like an uninhabited island. When sailors draw alongside, the creature sinks. The sudden descent creates whirlpools and rough water strong enough to damage or overturn a ship. The story warns that what seems solid on the open sea may not be land at all. Centered on an encounter off Awa, it is told beside reports of giant fish near Ezo and other variants, including one called Akaei no Kyō. The old accounts say little about Akaei's ecology. Three features remain constant: its extraordinary size, its movement between surface and depth, and the dangerous waves produced when it disappears. Natural history and ghost story meet in the image of a vast shape that no sailor can safely identify from afar.