Why Is the Umibozu a "Monk"? The Great Round Shadow on the Night Sea

Think about it for a moment, and the umibozu's name is odd. It's a giant yokai of the sea, yet it's called a "bozu," a Buddhist monk. Of course, the stories aren't about a monk climbing out of the waves. Instead, the name seems to hold the very shape of something people once saw on the sea at night.

"Bozu" means a round, shaven head

"Bozu" first meant a monk at a temple, but a round, shaved head is also called a "bozu-atama," a monk's head. The umibozu of legend is almost always described the same way: a dark, round head with no hair. The stories rarely mention hands or feet, and its face is often said to be hard to make out.

In other words, the umibozu seems to be a yokai named for a shape: "something big and round rose up out of the sea." The outline is round, but the details can't be seen. When people told others what they'd seen on the night sea, "a head like a monk's" was probably the easiest way to get it across.

A family of giant monks

Japanese yokai include plenty of big, round-headed figures. The "o-nyudo," a giant you have to crane your neck to see, and the "mikoshi-nyudo," who grows taller and taller the longer you look at him, are both told of as monks or "nyudo." A nyudo was originally someone who had entered the Buddhist path, which meant someone with a shaved head.

In some places the umibozu is also called "umi-nyudo," the sea nyudo. Perhaps that's because it was thought of as one more member of this family of giant monks, the one that appears at sea. Just as the o-nyudo on land looms in front of travelers on a night road, the monk of the sea rises up in the path of a boat.

What did people see on the night sea?

There are many ideas about what the umibozu really was: a wave suddenly swelling into a great hump, a rock or an island looming through the fog, a whale showing its back above the water. Out on a dark sea, it's hard to judge size and distance, and even familiar things can take on unexpected shapes.

Of course, no one can say which of these it was. And for the fishermen and sailors who passed these stories down, what mattered more than whether it was a trick of the eye may have been a simple feeling: out on the sea, anything can happen.

"Below one plank lies hell"

There's an old Japanese saying about how dangerous a sailor's work is: "Below one plank lies hell." Beneath the single board of the boat's floor is the deep sea, and if you fall in, there's no coming back.

For people who worked on a sea where the weather could change in an instant, a tale about the calm water suddenly swelling and a huge dark shape rising up must have hit close to home. Part of the umibozu legend, it seems, has long served as a warning: never take the sea lightly, and never push your luck by setting out when you shouldn't. You'll find tales of what happened to the boats that met it on the umibozu's Yokaipedia page. Along the shores of western Japan, there are also tales of yokai that appear on beaches at night, such as the ushi-oni.

Dark, but not pure black

Here at Pixel Yokai, we drew the umibozu as a huge head of deep indigo on a white background. We didn't make it pure black because a shadow seen on the night sea isn't truly black: it's a dark color mixed with the sea and the sky. There's just a little shine on the top of its smooth head. And next to the tiny boat at its feet, we hope you can feel just how big it is.