Notice of Apology and Advisory Regarding the Potential Leakage of Customers’ Personal Information from Temairazu, Inc.
[Important] Apology and Security Notice from Temairazu, Inc. Regarding a Possible Leak of Guests’ Personal Information
Thank you very much for choosing Hotel Sunoak Minami-Koshigaya.
We have confirmed that, in the reservation management system “Temairazu” used by our Hotel, there may have been an external leak of guests’ personal information. This was not due to unauthorized access to the Hotel, but rather unauthorized access to Temairazu, Inc., the company that provides the reservation management system.
We sincerely apologize for the significant inconvenience and concern this may cause.
Within the scope confirmed at this time, we have identified cases in which suspicious messages were sent to Reservers for some Reservations that meet all of the following conditions:
- Reservation date: Reservations completed on or before September 21, 2026
- Stay date: Reservations with stay dates on or after September 21, 2026
*As of September 28, 2026, the cause has been identified and measures have been implemented to address it along with additional security enhancements. Reservations can now be made normally.
If you receive any suspicious contact (email, SMS, etc.) claiming to be from Mori Eight Co., Ltd., our operating company, or from an Accommodation provider, please take special care regarding the following:
The confirmation emails we send at the time a Reservation is completed and on the day before arrival are sent only from addresses with the domain “@sunoak.net”. We will not send messages from any other email address.
[Important Precautions]
- Do not open any URLs or links included in such messages
- Do not enter credit card details or personal information
- Do not reply to suspicious messages
- Do not make payments or transfers as instructed by such messages
- If you need to check your Reservation details, contact your booked Accommodation directly or reach out to your booking site’s official support desk
For inquiries regarding this matter, please contact:
Temairazu, Inc.
https://www.temairazu.co.jp/pdf/1206/news-update
Department: Emergency Response Desk
Email: helpdesk@temairazu.com
We again sincerely apologize for causing you concern.












