The Kurono Grand Hagane watch takes inspiration from the ancient sword making techniques.

Japanese swords are made from very high purity steel called “Tamahagane”. This steel is produced from an ancient Japanese tradition. Tamahagane (玉鋼) means precious steel.


Grand:Hagane urushi design is inspired by “Tamahagane”. The dark amber hue of the Grand:Hagane dial reveals a subtle yet visually stunning urushi design. The unique urushi dial pattern was designed to resemble the rare and distinctive tobiyaki spots commonly seen inthe hitatsura style of hamon.

This time, Hajime Asaoka-sensei designed and implemented this “Tamahagane” image pattern for the urushi dial. Some people carry “Tamahagane” as a good luck charm because of its “stone language”. It has the meaning of “turning negative environments and emotions into positive outcomes,” and it also contains Hajime-sensei’s wish and sincerity during these challenging times.


Hajime-sensei’s ancestors were swordsmiths. His interest in Japanese swords is also the starting point of his metalworking techniques in watchmaking and the Grand:Hagane serves as an homage to his ancestors.

Continuing from the Kurono Grand:Akane watch, the beautifully finished Urushi lacquer dials are handcrafted piece by piece by craftswomen in Kyoto who inherited the Kyoto-style Japanese lacquer technique.


Kyoto lacquerware is based on a technique introduced from the Tang Dynasty in the Nara Period (710-794) and has been handed down from generation to generation for more than a thousand years based on Kyoto’s unique aesthetic sense.

The beautiful Urushi lacquered finish depends on the excellence of the polishing process. To polish it, they first find a small piece of charcoal without impurities. Then, the dial is polished using only human fingertips. The work is so delicate that even the slightest wisp on the fingertip can cause striations on the dial, which would have to be rebuilt from scratch. This is one reason why there is such a large rejection rate during the QC process.

Urushi lacquer is made from the filtered sap of the Japanese rhus vernicifera tree. The lacquer absorbs moisture from the air as it hardens, making the lacquered surface perpetually shiny and slick. Over time, urushi will become harder and more scratch-resistant as the curing process continues even after the initial manufacture.


The black lacquer used in this project is called “Roiro,” which is a chemical reaction in which iron oxide is added to raw urushi and the iron turns the lacquer black. In Japan, this traditional coloring method has been used for a long time to produce a clear and transparent lacquer.

This time, the process of applying several thin layers of Roiro Urushi lacquer and polishing it is used so that the design of “Tamahagane”, the base material, is slightly transparent. The metallic shine of the base metal is covered with a veil of lacquer that shines as if it were wet, allowing us to enjoy the various expressions of the tama-koh patterns depending on the light. Sunlight – specifically UV light – will, over time, lighten and make it more translucent and warmer or cooler.


Indices on the dial display for the first time display a complex character font called “Koji”, which was introduced from the east to Japan in ancient times. Even now, due to its complexity, it is still used in Japan for important documents to prevent the rewriting of amounts.

Technical details

Model: Kurono Grand Hagane

316L high-polished stainless steel case
Case diameter: 37mm
Thickness: 7mm excluding sapphire
Glass: Sapphire crystal
Special embellished caseback
Water resistance: 3 ATM

Hand-applied urushi lacquer dial with hamon design

Premium-grade Miyota 90S5 Japan-made mechanical automatic movement
Power reserve: 40 hours
Jewels: 24 rubies
Frequency: 28,800bph

Hours, Minutes, Seconds

Black calf leather band
Buckle: Pin buckle
Strap width: 20/16 mm

Launch date
December 2021

Made in Japan