Daiichi Kosho, a major Japanese karaoke company known for operating the popular Big Echo chain, has disclosed a potential data breach that could affect approximately 8.7 million records. The incident involved malware discovered on a computer belonging to Nippon Columbia Group (NCG), an entertainment company that handles customer information on Daiichi Kosho’s behalf.
In a statement published on October 8, 2026, Daiichi Kosho said it could not rule out the possibility that personal information stored on the affected computer had been exposed to unauthorized parties. But the company has not confirmed that the data was actually stolen or leaked.
“According to NCG, between October 1 and October 2, 2026, a malware infection was discovered on one of their employees' devices (a PC), and the device was isolated from the network on October 2. Following an investigation into the scope of the impact by NCG, we received a report from NCG on October 5,” read the statement.
Incident details
After an initial investigation, NCG informed Daiichi Kosho about the incident on October 5. The investigation revealed that information collected through outsourced business operations had been temporarily stored on the compromised computer.
NCG has reset affected passwords and is investigating how the malware entered the system, whether information was accessed by unauthorized individuals, and the overall scope of the incident. The available information does not identify the malware.
What can be leaked?
Daiichi Kosho estimates that approximately 8.724 million records may have been affected. “Based on the information we currently have, approximately 8,724,000 customers who registered or made reservations at our stores may have had their names (registered names), genders, dates of birth, email addresses, and telephone numbers leaked to external parties,” the company warned.
The affected records are linked to customers who registered for membership or made reservations at the company’s establishments. The businesses include Big Echo, DK Dining, Mega Big, Karaoke Club DAM, Banana Club and B-Garage.
How to stay safe?
Daiichi Kosho has warned customers not to open unfamiliar links or attachments and to remain cautious when receiving unexpected emails, text messages or calls. The company has also clarified that passwords and credit card information are not included in the potentially exposed data.