I read on CNN, and Bloomberg that he declared his income in USD (He paid himself in USD), 3 months after Nissan quietly changed its declaration of earnings policy, and forced executives to declare income solely in Yen. Ghosn said he usually declared his earnings in USD with Renault, Nissan, and other companies for years before this tragedy.
And this is what supposedly what landed him in jail. As opposed to child rapists that are given bail, and psychotic cannibals that walk away without a slap on the wrist.
For a while before the USD Yen fiasco that was claimed, the authorities couldn't release any information, people thought he was just being detained because it was a coup, pretty sure it was both. TBH.
Later, I started hearing stories of lavish spending on paintings, and corporate vacations with his male assistant in chief, and the round table (the same people that accused him). I don't know if these claims were legitimate, or they were just trying to paint him as an embezzling evil foreigner.
He was one of the people responsible for giving the economy a boost, he was regarded as a foreign savior, and look at how they used him up, and threw him away. Sort of like the English teaching industry, it's a bloody parallel.
For months after that, all I saw was the NHK showing gold bars of money, trying to explain why Carlos Ghosn is bad, with a panel of people commenting, and exaggerating their reactions. It's safe to say that if you need to make a panel on the NHK every afternoon explaining what exactly happened, and trying to convince people, there's obviously something fishy going on.
Students of mine were telling Carlos Ghosn is a bad man, and I asked them : Why is he bad? Student: He is criminal! Me: Why? Student : I don't know.
All this situation accomplished was a method to paint a foreigner in a bad light, even though there's no evidence of such.