TOKYO • The prosecutor aiming to take down former Nissan chairman Carlos Ghosn is known as the "ace of aces", a high-flier in an elite special department that deals only with the most high-profile cases.
Mr Hiroshi Morimoto, who also enjoys a reputation as "Mr Clean", has been in charge of the special investigation section of the Tokyo prosecutors office for just over a year, and now faces one of the biggest cases of his career.
In his early 50s with black hair flecked with grey, Mr Morimoto runs a team of 20 top officials investigating the complex and multifaceted case of alleged financial misconduct by the auto industry tycoon.
"It's the cream of the crop of investigators," said Mr Yasuyuki Takai, a former member of the unit and now a lawyer.
It was members of Mr Morimoto's team, dressed in dark suits, who rushed up the steps of Ghosn's private jet at Haneda Airport and whisked him away for questioning.
Grainy images at the airport were captured by the Asahi Shimbun daily, and the surprise arrest stunned Japan and the business world in general.
Mr Takai said the special investigations unit was split into three sections, dealing with corruption, white-collar fraud and tax evasion. Only the first two are working on the Ghosn case, which does not involve allegations of fiscal fraud.
The office has a record of securing high-profile convictions.
Until now, the unit's biggest case was arresting former prime minister Kakuei Tanaka in 1976 for his part in an immense global bribery scandal involving US aerospace company Lockheed.
It also discovered and dismantled a complex cartel of firms involved in rigging bids for building a high-speed train between Tokyo and the western city of Osaka.
Ghosn's case has sparked huge international interest and led to criticism from abroad of the Japanese legal system, which allows the authorities to detain suspects for long periods without formal charges.
Mr Morimoto, who keeps his cards close to his chest, has not made any public comment on the case to date.
He also did not address the court during a special hearing on Tuesday held to explain the reasons behind Ghosn's continued detention.
This has not prevented hordes of reporters from camping outside his home in the hope of gleaning a nugget of information.
One of the quirks of the Ghosn case is that Mr Morimoto now finds himself in a game of legal cat-and-mouse with his former boss: Mr Motonari Otsuru, a former head of the special unit and now the lead defence lawyer for the former Nissan chief.
The two men have contrasting personalities, according to Mr Masaru Wakasa, a lawyer, political figure and well-known TV personality who worked with them both.
Mr Wakasa told local media that Mr Otsuru is "calm and analytical", certainly the image the defence lawyer displayed to the press during his only news conference on Tuesday.
In contrast, Mr Morimoto is described as "passionate and a go-getter", not shy of speaking the truth to power.
"I had a few arguments with him when I was his boss," Mr Wakasa said.
Former unit member Mr Takai said: "They are rivals, but in the battle they are fighting it is not the person with the strongest force of character that will prevail, but the person who collects the most evidence to convict or acquit Ghosn."