The Yomiuri Shimbun has finally gone on record about Jake Adelstein with Belgian newspaper, “Le Soir” in an article dated 9/06/2023. The follow are some quotes (English translation from original in French) from the Yomiuri.

“There are descriptions whose veracity is impossible to verify, and other descriptions in which the author has distorted or embellished real facts. There are many of these. We also note his willful abandonment of absolute secrecy regarding sources of information, the most important and respected professional ethic in journalism,”

“According to what we checked in our databases, we counted 150 articles signed by Jake Adelstein. Of these 150 articles, only two were about yakuza.” Describing the American as a local affairs reporter: “Mr. Adelstein started with our company in 1993. He first worked at the Urawa local office in Saitama Prefecture, was part of the corporate department from June 1999 and resigned of his own accord in November 2005.”

“As for reporting on crime caused by the [yakuza], gun crime or drug trafficking, this was handled by other journalists,”

The Yomiuri also debunked Adelstein’s claims about his test scores on the company entrance exams, namely that he scored better than many Japanese applicants:
“The results were never officially announced, either publicly or to him (Jake) personally”.

Source: https://www.lesoir.be/518473/article/2023-06-09/infiltre-chez-les-yakuzas-le-journalisme-flou-du-justicier-jake-adelstein