Kobunken, the publisher, released an explanation and apology from author Jun Shimabukuro, a professor at the University of the Ryukyus, on October 10 about its decision to recall and discontinue the book “The System of Irresponsibility and the Battle of Okinawa.” Shimabukuro said he used three nonexistent court cases generated by AI in class materials, then included them in the book without checking or scrutinizing them.

The cases appeared on pages 147–149 in a supplementary section at the end of Chapter 3, titled “Okinawa Politics” class handout. They concerned international court records about the massacre of Okinawan residents accused of being spies during the Battle of Okinawa. Shimabukuro said he entered the URL of Stanford University Library’s database of international criminal trial records into a generative AI system and asked it to provide examples of Japanese military killings of Okinawan residents. The AI produced cases in English, which he mistakenly believed had been retrieved from the database and used.

Shimabukuro said he first used the cases in class materials and later copied them into the book without verification. He apologized, saying he had failed to engage carefully with historical sources and to exercise the caution expected of a researcher. His statement did not identify the AI product or model.

According to Shimabukuro, the recall and discontinuation were decided on September 18, and Kobunken announced them on September 24. An October 10 update disclosed how generative AI had been used and that the class materials also contained errors. Shimabukuro said he asked his department to email students who took the course, including graduates, with a correction and apology.

Shimabukuro is reviewing other parts of the book for errors in passages where AI was used and says he will make a further announcement if any are found. Kobunken said it would strengthen proofreading and editorial review for all manuscripts, not only those involving AI. The publisher is asking buyers to return copies with shipping paid on delivery and is offering refunds.

Kobunken, the publisher, released an explanation and apology from author Jun Shimabukuro, a professor at the University of the Ryukyus, on October 10 about its decision to recall and discontinue the book “The System of Irresponsibility and the Battle of Okinawa.” Shimabukuro said he used three nonexistent court cases generated by AI in class materials, then included them in the book without checking or scrutinizing them.

The cases appeared on pages 147–149 in a supplementary section at the end of Chapter 3, titled “Okinawa Politics” class handout. They concerned international court records about the massacre of Okinawan residents accused of being spies during the Battle of Okinawa. Shimabukuro said he entered the URL of Stanford University Library’s database of international criminal trial records into a generative AI system and asked it to provide examples of Japanese military killings of Okinawan residents. The AI produced cases in English, which he mistakenly believed had been retrieved from the database and used.

Shimabukuro said he first used the cases in class materials and later copied them into the book without verification. He apologized, saying he had failed to engage carefully with historical sources and to exercise the caution expected of a researcher. His statement did not identify the AI product or model.

According to Shimabukuro, the recall and discontinuation were decided on September 18, and Kobunken announced them on September 24. An October 10 update disclosed how generative AI had been used and that the class materials also contained errors. Shimabukuro said he asked his department to email students who took the course, including graduates, with a correction and apology.

Shimabukuro is reviewing other parts of the book for errors in passages where AI was used and says he will make a further announcement if any are found. Kobunken said it would strengthen proofreading and editorial review for all manuscripts, not only those involving AI. The publisher is asking buyers to return copies with shipping paid on delivery and is offering refunds.