Japan's Supreme Court to test use of generative AI in civil trials

The Supreme Court of Japan has requested ¥60 million for fiscal 2027 to test generative artificial intelligence in civil trials, aiming to streamline and shorten proceedings. While a previous mock test by district court judges in early 2026 showed AI can assist in drafting summaries, it also warned of risks like reinforcing biases and omitting key facts. The court's broader budget request includes ¥38.7 billion for trial digitalization across criminal and domestic cases.

Supreme Court AI Trial Test

• ▪The Supreme Court of Japan will develop a system alongside its artificial intelligence testing to prevent the leakage of personal information and corporate trade secrets.
• ▪The Supreme Court of Japan's fiscal 2027 budget request includes approximately ¥38.7 billion for expenses related to the digitalization of trial procedures.
• ▪The Supreme Court of Japan announced on August 31, 2026, a budget request for fiscal 2027 that includes approximately ¥60 million to test generative artificial intelligence in civil trials.
• ▪The Supreme Court of Japan plans to conduct a demonstration test in fiscal 2027 using records of settled lawsuits to examine the utility of generative artificial intelligence.
• ▪The requested ¥38.7 billion digitalization budget for the Supreme Court of Japan will cover trial procedures in both criminal and domestic cases.

Civil Trial Efficiency Improvements

• ▪Masayuki Nagata of the Supreme Court of Japan's digital policy planning office stated the court hopes to present the results of its artificial intelligence demonstration test within fiscal 2027.
• ▪Masayuki Nagata of the Supreme Court of Japan's digital policy planning office stated that using artificial intelligence is expected to streamline and shorten prolonged civil trials.

AI Judicial Bias Risks

• ▪A research group of six midcareer judges from the Tokyo and Osaka district courts conducted a mock trial test in January and February 2026 to evaluate artificial intelligence.
• ▪The research group of judges from Tokyo and Osaka found that artificial intelligence could reinforce biases by omitting important facts and providing plausible yet incorrect answers.
• ▪The research group of judges from Tokyo and Osaka concluded that artificial intelligence should be positioned as an assistant to judges rather than a replacement.

AI Document Summary Creation

• ▪The planned artificial intelligence system for the Supreme Court of Japan will be used by judges and officials to generate lists of points of contention from lawsuit documents.
• ▪During the planned demonstration test, judges and officials of the Supreme Court of Japan will input documents into an artificial intelligence system to create rough drafts of record summaries.

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