The government of Japan released The Status Report of Plutonium Management in Japan - 2023 report, which details its plutonium holdings. According to the report,

As of the end of 2023, the total amount of separated plutonium both managed within and outside of Japan was approximately 44.5 tons, approximately 8.6 tons of which was held domestically and the rest of approximately 35.8 tons was held abroad.

This is a decrease of 0.6 tons from the total of 45.1 tons that Japan reported having in 2022. The amount of plutonium held in Japan decreased as well, from 9.3 tons in 2022. This is due to 0.6 tons of plutonium in MOX fuel loaded into the Takahama Unit 3 reactor.

Of the plutonium stored abroad, 14,097 kg are stored in France (14,113 in 2022) and 21,735 kg - in the United Kingdom (21,757 in 2022).