Protip - you should care if he raped 12 nuns! Japan's justice system, while certainly has issues is universally considered to be one of the worlds' fairest. Their high conviction rate is solely due to taking so few cases to judgement as most plead out.
Not so - Japan's [criminal] justice system is absolutely not "universally considered to be one of the worlds' fairest". Cite any authoritative source for claiming that. Most sources I found cite the Nordic countries or other W European countries.
(A high conviction rate at trial in Japan is merely due to not having a right-to-silence, imprisonment till trial, prosecutors discretionarily dropping some cases.)
Most of the stereotypes of the Japanese justice system are outdated, and it's pretty funny to hear one of the wealthiest people in the world claim he wouldn't get a fair trial there while he was walking free with unrestricted access to his lawyers after numerous arrests for serious financial crimes.
"universally considered to be one of the worlds' fairest" is not accurate, and "good by Asian standards, but not as good as the North European average" is more like it.
It is not stereotype but simple fact to state that Ghosn was held for questioning for a ridiculously long time by Western standards: 129 days over two periods in the Tokyo Detention House, of which 53 before indictment. Eight hours a day questioning, with no defense lawyer allowed to be present. You might somehow incriminate yourself if that was done to you too.
Ghosn was absolutely a special case: it was extremely plausible that he wouldn't get a fair trial there, as he was the highest-profile (non-Asian) foreigner in Japanese industry, with saturation international media coverage, and moreover there was major protectionism within the two car companies against operationally merging with Renault and actually having plant closings and major layoffs in one of Japan's most sacred industries, which also reportedly incurred high-level opposition from government. (This is not commenting on the specifics of Ghosn's financial case.)
And again, the fact that few high-profile white-collar cases go to trial but end in a plea (which you say is a virtue of the Japanese system) makes it hard to predict what might have happened, both evidence admissibility, verdict and sentence. Certainly unlikely he would have gotten a suspended sentence, if convicted.
UPDATE: Japan’s prosecutor reportedly repeatedly broke the law by leaking details of the case against Ghosn. Which pretty much corroborates both "wouldn't have gotten a fair trial" and "high-level political opposition".
UPDATE 2: RP was one of a handful of Nissan insiders who knew about the planned arrests beforehand: "I was called into Hari Nada's office…and told there was going to be a dramatic arrest. Arranged for maximum publicity... When you lie to someone, to get them back into a particular jurisdiction, so that you can have them arrested in a very public manner, that says a lot about what's going on." [0]
