Ryuhyo · Hatsukokoro · kiritsuke
Ryuhyo: drift ice, written in steel
16 July 2026
Every winter, the sea itself drifts a thousand kilometres south to Hokkaido. Hatsukokoro named this blade after that arrival — and began it as a cloud of steel powder.
Each winter, ice born in the Sea of Okhotsk drifts south until it reaches the coast of Hokkaido — the southernmost drift ice in the Northern Hemisphere. The Japanese call it ryūhyō. For a few weeks, the sea itself arrives. That is the name Hatsukokoro gave this blade, and its mirror-polished damascus face moves exactly like it.
The strangest fact about this knife: its steel began as powder. SG2, from Takefu Special Steel in Echizen, is made by atomising molten steel into a fine metal dust, then fusing it back into a solid — so its carbides stay uniform and small. That is what lets the edge be taken thin and hard (62–64 HRC) without turning brittle. A blade that started as a cloud, frozen into order — much like drift ice.
The rainbow on its face is metal, not paint: an electroplated finish over the damascus that shifts as the light moves. And as the blade is sharpened over the years, bare steel emerges at the edge — by design, the way sea ice gives way to water.
One more thing most guests never know: the kiritsuke profile, with its angled tip, was traditionally the one knife reserved for the head chef alone. Handing it to anyone else simply wasn't done.
This piece rests in the Reserves, held for one Patron at a time.