So I was just working up a little tomonagura slurry today, and I guess it felt a little lonely because all of a sudden I was holding two tomonagura in my hand instead of one. I ain't no geographist, but it seems they reproduce asexually.
Luckily the rock was big enough that I could clean up some surfaces and make them both usable.
The splitter (unknown stone) is sitting on my Wakasa, and a nearby Nakayama tomonagura came over on a Shobu to give its congratulations.
http://i.imgur.com/u4qvoOG.jpg