Mizugumo and Mizukaki – the Ninja’s “Mud Sandals”

Real ninjas (also known as “shinobi”) used a variety of special tools, many of which were useful when the ninja needed to infiltrate a castle or other fortified area–either for purposes of assassination or for other acts of espionage.

When crossing swampy castle moats or weed-filled rivers, ninjas often used mizugumo or mizukaki – two different but similar types of shoes designed to help traverse an overgrown or marshy waterway.

The larger mizugumo operate on a principle similar to snowshoes.


The wooden rings around the inner “shoe” spreads out the wearer’s weight, enabling the ninja to cross swampy areas without sinking. 

Ninja on Mizugumo

Unfortunately, mizugumo are fairly large and difficult to conceal. For this reason, ninjas also developed the smaller mizukaki:


While not as effective at distributing the wearer’s weight, and thus useful only on heavily overgrown areas (or marshes where the problem was avoiding getting stuck in mud, as opposed to crossing water), a ninja could hide mizukaki in a tunic or small pack, making them a useful tool that was also easily concealed. 

I took these photographs at the Iga Ninja Museum in Iga, Japan–the historical home of the Iga ryu, one of Japan’s most famous ninja clans–while researching my upcoming Hiro Hattori mystery, Betrayal at Iga. In the novel, which releases July 11, 2017, Hiro and Father Mateo visit Hiro’s home in Iga. When a member of the rival Koga ryu is murdered during peace negotiations between the clans, Hiro and Father Mateo must catch the killer in time to prevent a ninja war. 

Unfortunately, I wasn’t able to work either mizugumo or mizukaki into this particular novel, but I’m looking forward to letting Hiro use them in a future book!