Ninja are mysterious. There are things we know and things we don't. But the notion that some have about these ninja water shoes is supposedly incorrect.
In Japanese, these flotation devices are called mizugumo (水蜘蛛), which literally means "water spider", and are believed to have been used while crossing castle moats.
— ひな@Gungnir (@HinaKajiro_FF14) December 6, 2016
Sankei News reports that it's generally thought that ninja would put their feet on each mizugumo's centre board and, literally, walk on water.
— hirodqn (@naminori_banana) January 4, 2015
Which seems difficult.
— 毎日新聞＠みえ (@Mainichi_Mie) August 21, 2016
Or, uh, pull themselves across.
— 宮本 亮 (@Sadwarlock) September 2, 2016
— 29Q小林＠フォーオナー【大蛇】 (@29Qkobayashi) December 13, 2016
Which also seems difficult.
— 毎日新聞＠みえ (@Mainichi_Mie) April 9, 2016
Or it's thought mizugumo could be used with poles.
— ミカンちゃんのミカンジュース飲みたい (@anaikcorttiw) June 6, 2016
— 好爺 (@yin00034) June 23, 2016
However, according to ninja scholar Atsumi Nakajima, this isn't how mizugumo were actually used.
Nakajima has been collecting old ninja documents, and has discovered that the word "sit" (座る or suwaru) is written in mizugumo's middle section, which is where people have been putting their feet. They should have been sitting!
"Ninja would get in one mizugumo, put flipper-type shoes on their feet, and move across the water's surface," Nakajima believes.
[Image via Sankei News]
So, this is actually a floaty. For ninja. Heh.
Online in Japan, many people seemed surprised by this, adding that they thought the proper way to use a mizugumo seemed "dorky" and "uninspiring".
Note that the floaty explanation isn't exactly brand new.
@日本科学未来館#THE NINJA#コトミちゃん pic.twitter.com/FTCtB1qSxv
— コトミちゃんトコトコさんぽ (@kotomitokotoko) July 2, 2016
Even though the notion that mizugumo were worn like shoes does still appear to dominate in Japan, this latest Sankei article might help change that!
— 山本かつお (@ykatsuo1975) March 17, 2016
As Kotaku previously pointed out, the popular notion of ninja isn't always exactly "correct", so it isn't surprising to see how popular culture has created a different interpretation of mizugumo.