Real "ninja" sword, or modern invention?

[fearn]

Hi All,

Found another weird sword, and I'm wondering how real it is.

The sword I'm posting below is claimed to be a special "ninja" weapon invented by the Saito family in Medieval Japan, and possibly of supernatural origin (see link to picture and story).

I'm talking about the middle sword in the picture. It's a "backwards" katana: 2/3 handle, 1/3 blade, and the blade is double-edged. It is used differently than a katana (search for "tengu sword" on Youtube). The one shown is obviously is a modern model.

A school teaching the use of this weapon exists, but some martial artists believe that the system is modern, and that the "tengu sword" is based on the knives used to harvest cane and pineapple in Hawaii--cane knives and machetes, in other words.

My question to the board is: has anyone ever seen a genuine, historical Japanese (or other) sword that looks like this? If you think it's modern like the "ninjato" above it, what do you think it was based on? It doesn't look like a cane knife or machete to me.

Best,

F