22/09/2026
Your trust matters to us. We’re sharing this official notice from Yamamasa Koyamaen to help you shop with confidence and understand the new security seals on its 150g and 300g matcha tins.
Our latest delivery still includes tins with an April 2027 best-before date. These were supplied without the new seal, as explained below.
Swipe to see the update, save it for reference and share it with fellow matcha lovers so they know what to expect. 💚
ENGLISH TRANSLATION OF THE NOTICE
Introduction of security seals on 150g and 300g matcha tins
Yamamasa Koyamaen Co., Ltd.
To our valued business partners,
We wish you continued prosperity and sincerely thank you for your ongoing support.
Our products are increasingly sold through various channels in Japan and overseas. To protect authorised retailers and consumers from fraudulent sales involving unauthorised replacement of the contents, we are introducing security seals to indicate opening on our 150g and 300g matcha tins.
1. How the seal works
The seal is attached across the lid and body of the tin. Once peeled off, it leaves the characters 「開封済」 (“Opened”) on the tin.
Even if a seal of the same design has been reapplied, a product may not be genuine if these characters do not remain when it is removed. Please refer to the example photographs.
2. When application begins
Seals will be applied to products with best-before dates of May 2027 onwards, followed by June 2027, July 2027 and subsequent dates.
Products with best-before dates of April 2027 or earlier will not carry this seal.
3. Please check products upon receipt
For products with best-before dates of May 2027 or later, please contact Yamamasa Koyamaen for confirmation if:
• No seal is attached.
• The characters 「開封済」 (“Opened”) do not remain after removing the seal.
This initiative aims to maintain legitimate distribution and give consumers peace of mind. We appreciate your understanding and cooperation.
Yours faithfully,
Yamamasa Koyamaen Co., Ltd.
Enquiries: Sales Department
0774-24-1122
Photo labels: “Security seal” / “Condition after opening”