Editor’s Note
This article provides an overview of Castem Co., Ltd., a Japanese manufacturer specializing in advanced precision casting and molding technologies, including 3D printing applications.

Castem Co., Ltd., headquartered in Fukuyama City, Hiroshima Prefecture, is a company that manufactures lost wax precision casting parts, ceramic injection sintered parts, MIM (Metal Injection Molding) parts, and FRP injection molded products. It has also been engaged in new manufacturing utilizing 3D printers.

“KOHKOH” prioritizes sustainability and strives to create environmentally conscious jewelry. Using self-cultivated pearls as the primary material, the brand incorporates new perspectives and technologies, aiming to harmonize with nature and leave a beautiful Earth for future generations. The brand’s overall producer, Takatsugu Kojima, grew up in Kyoto and studied architecture and jewelry design. He has exhibited his works at galleries and art fairs both in Japan and abroad and has collaborated with contemporary artists.
Typically, the mother-of-pearl shell is discarded after the pearl is extracted, but “KOHKOH” makes efforts to minimize this. Using high-precision processing machines, it has succeeded in creating cameos using the mother-of-pearl shell, working towards sustainable jewelry production.

Products include “Light Ring Octagon” (440,000 yen, K18 gold, crystal, pearl) and “Cut Cameo Pendant no1” (220,000 yen, silver, mother-of-pearl, crystal).
This event is a B-to-C event showcasing designers’ creativity and innovation, with approximately 120 exhibitors participating. The venue is Omotesando Spiral, and the event period was from December 1 to 3, 2023.

This is an overview of the new jewelry brand “KOHKOH” by Castem Co., Ltd. This brand is bringing a new wave to the modern jewelry industry with its innovative technology and sustainability-focused approach. In particular, the fusion of 3D printing technology and pearl cultivation enables creative expression beyond traditional frameworks, and its unique designs are highly regarded. Furthermore, its efforts to utilize discarded mother-of-pearl shells highlight the importance of sustainability in the jewelry industry.