Japan megabanks near Anthropic Mythos access after Bessent Tokyo visit

Japan’s three megabanks are likely to gain access to Anthropic’s Mythos AI model after U.S. Treasury Secretary Scott Bessent’s recent Tokyo visit, Bloomberg reported May 13, 2026, citing a person familiar with the matter. The move would extend access to MUFG Bank, Sumitomo Mitsui Banking Corp. and Mizuho Bank, marking a major expansion of a tool that has raised cybersecurity concerns. Mythos, released on a limited basis in April 2026 under Anthropic’s Project Glasswing, can detect software vulnerabilities at a level that has prompted concerns it could be misused to target critical infrastructure. JPMorgan Chase & Co. was the only bank in the initial access group. Nikkei reported access could be granted by May 31, 2026. Anthropic, Mizuho and MUFG declined to comment. Sumitomo Mitsui Financial Group CEO Toru Nakashima said on May 13 he was unaware of access details but said the bank has formed an internal Mythos working group.