Japan's three megabanks are moving to secure access rights to Anthropic's new AI model, Claude Mythos [1].
This shift represents a critical effort to synchronize the adoption of advanced generative AI with national security protocols. Because these models can be used to create sophisticated cyberattacks, the Japanese government is treating the integration as a potential systemic risk to the country's financial stability.
Mitsubishi UFJ, Sumitomo Mitsui, and Mizuho are the three institutions [1] pursuing the technology. Access rights to the model could be obtained as early as April 2026 [1].
To address the security implications, an emergency meeting was held on April 24, 2026 [2]. The gathering took place at the Financial Services Agency headquarters in Tokyo [3]. The meeting included Finance Minister Satsuki Katayama, Bank of Japan Governor Kazuo Ueda, and senior bank executives [1].
The primary objective of the meeting was to evaluate and mitigate potential cyber-security threats posed by the powerful AI model [4]. Officials said the capabilities of Claude Mythos could be exploited to target the financial system, necessitating a coordinated defense strategy between the central bank and private lenders [4].
By gaining direct access to the model, the megabanks intend to better understand its operational logic and vulnerability points. This proactive approach allows regulators to establish safeguards before the technology is deployed on a wider scale across the sector [4].
“Japan's three megabanks are moving to secure access rights to Anthropic's new AI model, Claude Mythos.”
The involvement of the Bank of Japan and the Finance Minister indicates that AI adoption in the banking sector is no longer viewed as a mere productivity tool, but as a matter of national security. By securing early access to Claude Mythos, Japan is attempting to build a 'defensive AI' framework to counter the potential for AI-driven financial crimes and systemic cyber-instability.
