Sole of the Ninja...
“Why do you wear those funny slippers / shoes?”
A common question for people starting or watching ninjutsu classes. On the surface it does seem a bit odd given that a majority of martial arts wear either nothing on their feet, protective footwear for competition, or traditional ‘kung-fu’ like slippers.
Some of the answer is ‘tradition’ as the art is a traditional Japanese art, and in these, like Kyudo (archery) they also wear indoor tabi at times. But, as with many things ninjutsu related, the answer goes a lot deeper than that.
Firstly, if you look at indoor tabi sourced from Japan you will notice a few differences to western manufactured ones.
The fastenings are called kohaze and resemble metal tabs that slip through a sewn string, not Velcro. This gives the tabi a better fit and is quiet to apply. The indoor tabi have cotton soles, not leather or synthetic materials. So, they are silent on polished floors. They also lend a sensitivity to the feet. When there is little between the foot and the floor it is easier to be aware of the surface, water, sharp objects and movement. There is no grip on the soles of the indoor tabi, which may seem a design flaw. However, cotton tabi when slightly damp have a good grip on smooth floors and again are quiet. To be able to move quietly it is important that the footfall is soft and sensitive to the surface.
There is a famous scene in the film Ninja Assassin where the child training has the soles of his feet struck with a bamboo cane, and this cuts them and makes them bleed.
On the surface this is just a sadistic punishment for making a noise, however there is more to it than this. The soles of the feet are quite sensitive but injuring them makes it very painful to step. This means that the next steps are taken with great care as its painful, and because the blood makes it slippy. While I would not condone the fictional action, it makes sense in that context.
If we look at outdoor tabi from Japan, we see some similarities.
The fastenings are the metal tabs, or kohaze, and the soles are a thin layer of rubber with a distinctive grip pattern. Now, you can get tabi with cushioned soles, almost like trainers, but you then loose the flexibility of the sole and the sensitivity. The grip pattern is designed to work on different surfaces. The more modern soles are very utilitarian and not as effective. I have, over the years, tried many different tabi, with Velcro, cushioned soles, suede soles etc. Each time they have proved to be less effective than the ones from Japan with thin soles and kohaze fastenings.
With traditional tabi you get a good feel for the surface, a connection to the environment, a good level of stealth and hopefully better taijutsu.
In ninjutsu you must see with more than just your eyes…