To always findthe next way forward


From a Leading
Jewelry Industry Firm

Kohsai factories are located
exclusively in Japan.
We harness our technological strength,
a fusion of craftsmanship and machining,
to maintain complete control over all
aspects of production: from quality,
to finishing, to flexibly responding to customer demand, and even to mass production.
We strive to improve the usability and reliability of our products as a technical jewelry company.

Jewelry parts

Appr. 50% share of domestic jewelry parts, with around 70% of earrings. We're taking on global markets as well.

Quality or quantity.Our technologies give us the unique ability to pursue both, as we focus on manufacturing for a number of major jewelry brands, producing more than ten million items a year. Not only do we have a strong presence in Japan, but we are also taking on global markets.


Overseas Transactions: With 500 companies across 14 countries and 13 regions
Items Produced: 10 million annually (total production to date of 130 million)

SKRAV features safe, pure silver in the form of Silver925

We painstakingly apply a rhodium plating to this nickel-free product to prevent allergic reactions.Our goal is to make sure anyone and everyone can wear this product safely, without incident.

SCRIPP , an earring part that's both durable and easy to adjust

SCRIPP is a powerhouse earring part, boasting 70% of our total company sales.It’s well-suited to any design, making earrings easier to put on and take off, and offering supreme durability.

Silicone Catches offer a reassured, safe experience

Our catch fittings are wrapped in silicone, a material frequently used in the medical field.They are designed not only to keep their shape and keep earrings’ holding power, but also to cause no burden on their wearers.