May 28 : Japan's three biggest banks - MUFG Bank, Sumitomo Mitsui Banking Corp and Mizuho Bank - are expected to gain access to OpenAI's latest model to defend against cyberattacks, the Nikkei newspaper reported on Thursday.

OpenAI's GPT-5.5-Cyber model heads to Japan's three megabanks as part of a US-Japan cybersecurity deal covering 15 critical infrastructure sectors.

OpenAI will provide its GPT-5.5-Cyber model to Japan's megabanks and government for cybersecurity, as AI-driven threats reshape the financial security landscape.