Multiple Japanese firms report massive data breaches affecting millions of users

GMO Research & AI Inc., an internet service firm in Tokyo, announced that hackers accessed its server and stole up to 948,500 member records, some of which were used to obtain Amazon gift-card codes valued at about 2.9 million yen. The following day, Mr Max Holdings Ltd., which runs a chain of discount stores, said a breach of its online-shopping server may have exposed personal data belonging to up to 1.7 million customers.

These disclosures come amid a series of recent data leaks in Japan: Monogatari Corp., operator of the Yakiniku King barbecue chain, reported that more than 10 million customer entries were leaked from its reservation and rewards app; the car-sharing platform Times Car saw about 1.6 million driver-license images of current and former members released; and delivery companies Yamato Transport Co. and Sagawa Express Co. warned that customer names, addresses and other details might have been compromised. The spate highlights growing cybersecurity challenges for Japanese businesses across sectors.