Dioscorea Nipponica is available at my local permaculture nursery.
Its a Yam, but its not the most reported on.

Rolling Hills Nursery,list it as edible.

PFAF gives it great review.

Does anyone here have experience with this plant?

That is also known as Shan Yao, one of the true Yams and it is very good food.
I would grow it, it also is a medicinal and the flavor is very nice.

I first found out about this yam from a Japanese family that lived across the street from me in California.
He and I exchanged a lot of methods and techniques over a 4 year period (I even worked at his nursery for a year).

Remember the leaves oppose directly across from each other on the edible species of true yams.

Redhawk

Thank you Bryant,I was worried about getting a dreaded "air potato" by another name!
Your familiarity with it is reassuring.
Did you use only the actual yam or did you also use the aerial tubers?

A side note, the foliage of sweet potatoes are edible, does that apply to yams as well?

I've done some research, and I think in addition to this plant, I will buy a variety of true yams from CAM and Jungle Jims, and plant them, just to see what works.

you can use both the flower (aerial tubers) and the root (actual yam) they have different flavors (both pretty dang awesome to my pallet).