(Maruka) Shou-hon-yama is the best grade stone from Nakayama sold by the sole miner of this mountain, Hatanaka Natural Sharpening Stones Stone Industry. Any Nakayama stone that has this stamp (unless it's a fake) is guaranteed of its highest quality. Maruka's (= circled "Ka") "Ka" is Kato's first character "Ka". Kato family is the owner of Nakayama quarry before Hatanaka family succeeded.

I named this stone Maccha Youkan (Green Tea Sweet Bean Jelly) for its close resemblance to this Japanese dessert, and made a box and signed and stamped.