Ninjas are famous for climbing walls with the ease and grace of a spider. According to legend, ninjas could scale even impossibly high, completely polished surfaces with ease. Some myths even claimed they could fly.
In reality, ninjas were highly trained assassins and spies–not supernatural beings with magical skills. They couldn’t fly, but they did possess the ability to scale walls that would stop most people, partly due to a set of metal claws called shuko (or, sometimes, shinobi shuko–since shinobi is the more traditional Japanese word for “ninja”).
Traditionally, shuko were made of metal. They consisted of metal bands (or occasionally, leather ones) which slipped over the ninja’s hands, with a set of spikes that protruded forward from the wearer’s palm. Like many ninja weapons, shinobi shuko were multifunctional. The claws gave the wearer a solid grip when climbing walls or trees, and also served as a weapon in hand-to-hand combat.
The ease and speed with which a shuko-wearing ninja could scale a wall and disappear helped add to the legends surrounding the ninja’s supernatural strength and amazing skills.
Ninjas really were strong, and agile, and highly trained in stealth and combat, but it was shuko and skill, not magic, that let them climb those walls so fast. Shinobi shuko were first developed during the medieval period, or possibly even earlier.
Some histories attribute the invention of this ninja tool to the Tokugare ninja clan, though the exact date and place of the claws’ invention has either been lost to history or remains a secret (like much historical ninja lore). Over time, the use of shuko spread throughout the different ninja clans. These, like other useful, multi-purpose weapons, soon became a standard part of the standard shinobi arsenal. The construction and appearance of the weapon varied, from clan to clan and over time, but the basic appearance and function of the tool was fairly constant. Among the common variations: use of leather rather than metal bands, adjustable claws (as opposed to fixed ones), and different numbers of claw spikes (usually from two to four, though five-clawed shuko did exist).
Many ninjas also used spiked foot bands to complement shuko when climbing or to aid with grip when hiding in elevated, precarious places. Spiked bands worn on the feet were called ashiko, and were usually designed to slip on over shoes or other footwear. In some cases, ashiko were designed with thongs that slipped between the wearer’s big toe and second toe–much like the thong on modern-day flip-flops–to help keep the spiked foot bands in place.
Whether worn on the hands or on the feet, the shinobi’s spiked bands facilitated climbing and aided the ninja in close combat. Although familiar to ninja fans, shuko and ashiko are less-well known to Westerners generally, even though most ninja would have carried them on every mission. Many popular myths and legends about the ninja are untrue. Their skill at scaling vertical walls, however, is one that has its root in truth. With the aid of shuko (and ashiko), Japanese ninjas really could run up a wall much faster, and with more confidence, than other people can.