Photo/Illutration Nissan Motor Co.'s global headquarters in Yokohama (Asahi Shimbun file photo)

For the first time, an individual who struck a plea bargain deal with prosecutors testified in a Japanese court trial, in the high-profile case involving Nissan Motor Co. and its embattled former chairman.

Prosecutors have built their case on testimony provided by Toshiaki Onuma, 61, who served as the head of the secretary’s office at Nissan.

Onuma worked closely with Carlos Ghosn, 66, the former company chairman, as well as Greg Kelly, 64, the former representative director who was a close associate of Ghosn.

Both are defendants facing allegations they conspired to underreport Ghosn’s remuneration as company chairman. However, because Ghosn jumped bail and fled Japan in a dramatic escape late in 2019, it is Kelly, as well as the Nissan company, that are actually standing trial.

Onuma's appearance in Tokyo District Court on Sept. 29 was the first time he has spoken in public since Ghosn’s arrest in November 2018.

Japan’s plea bargaining system only began in 2018 and Onuma is the first to provide testimony in court.

At the first court session, Kelly pleaded innocent to the charge of underreporting about 9.1 billion yen ($86.2 million) in remuneration for Ghosn.

At the Sept. 29 session, Onuma explained that in his role as head of the company secretary’s office, he handled payment of executive remuneration as well as personnel matters.

Regarding Ghosn’s remuneration, Onuma testified in court, “There was unpaid remuneration and we considered how to make payment while avoiding public disclosure.”

Onuma added that he consulted with and reported to Kelly about such matters.

Onuma avoided indictment by agreeing to cooperate with the investigation and testifying in court.

Prosecutors suspect that Onuma and Kelly played different roles in how to go about not revealing the remuneration to Ghosn.

Onuma is scheduled to appear in court 23 times until December.

At Kelly’s first appearance in court on Sept. 15, his lawyers asked the court to carefully assess the credibility of Onuma’s testimony.

The lawyers argued that Onuma would be testifying while always under the fear of being indicted on violating the Financial Instruments and Exchange Law as well as committing perjury if any of the testimony did not match what he told prosecutors during the investigation.

Under the indictment, Kelly is accused of underreporting 9.1 billion yen in remuneration for Ghosn between 2010 and 2017 on Nissan’s financial reports.

(This article was written by Wataru Netsu and Jun Miura.)